- \n
- \u5df2\u8bb2\u8fc7\uff1a\u6574\u6570\u3001\u5b57\u7b26\u4e32\u3001\u5b57\u7b26\u3001\u6570\u7ec4<\/li>\n
- \u672a\u8bb2\uff1aList\u7cfb\u5217\uff08\u5217\u8868\uff09\u3001Set\u7cfb\u5217\uff08\u96c6\u5408\uff09\u3001Map\u7cfb\u5217\uff08\u5b57\u5178\uff09<\/li>\n<\/ul>\n<\/li>\n
- \u9762\u5411\u5bf9\u8c61<\/li>\n
- \u5305\uff08Python\u7684\u5305\u548c\u6a21\u5757\uff09<\/li>\n<\/ul>\n
\u5173\u4e8eObject\uff08\u4e0a\u8282\u56de\u987e\uff09<\/h2>\n
\n
- \n
- \n
\u5728Python\u4e2d\u6bcf\u4e2a\u7c7b\u90fd\u9ed8\u8ba4\u7ee7\u627fObject\u7c7b\uff08\u6240\u6709\u7684\u7c7b\u90fd\u662fObject\u7684\u5b50\u7c7b\uff09\u3002<\/p>\n<\/li>\n
- \n
\u5728Java\u6240\u6709\u7684\u7c7b\u90fd\u662f\u9ed8\u8ba4\u7ee7\u627fObject\u7c7b\u3002<\/p>\n
int v1 = 123;\nString name = \"\u6b66\u6c9b\u9f50\";<\/code><\/pre>\n\u7528\u57fa\u7c7b\u53ef\u4ee5\u6cdb\u6307\u4ed6\u7684\u5b50\u7c7b\u7684\u7c7b\u578b\u3002<\/p>\n<\/li>\n<\/ul>\n<\/blockquote>\n
import java.util.Arrays;\n\npublic class Hello {\n\n public static void main(String[] args) {\n \/\/ String v1 = "wupeiqi";\n Object v1 = new String("wupeiqi");\n System.out.println(v1);\n System.out.println(v1.getClass());\n\n Object v2 = 123;\n System.out.println(v2);\n System.out.println(v2.getClass());\n }\n}<\/code><\/pre>\nimport java.util.Arrays;\n\npublic class Hello {\n\n public static void main(String[] args) {\n \/\/ \u58f0\u660e\u6570\u7ec4\uff0c\u6570\u7ec4\u4e2d\u5143\u7d20\u5fc5\u987bint\u7c7b\u578b;\n int[] v1 = new int[3];\n\n \/\/ \u58f0\u660e\u6570\u7ec4\uff0c\u6570\u7ec4\u4e2d\u5143\u7d20\u5fc5\u987bString\u7c7b\u578b;\n String[] v2 = new String[3];\n\n \/\/ \u58f0\u660e\u6570\u7ec4\uff0c\u6570\u7ec4\u4e2d\u53ef\u4ee5\u662f\u5fc5\u987bint\/String\u7c7b\u578b;\n Object[] v3 = new Object[3];\n v3[0] = 123;\n v3[1] = "wupeiqi";\n\n }\n}<\/code><\/pre>\n\u6240\u4ee5\uff0c\u5982\u679c\u4ee5\u540e\u60f3\u8981\u58f0\u660e\u7684\u6570\u7ec4\u4e2d\u60f3\u8981\u662f\u6df7\u5408\u7c7b\u578b\uff0c\u5c31\u53ef\u4ee5\u7528Object\u6765\u5b9e\u73b0\u3002<\/p>\n
import java.util.Arrays;\n\npublic class Hello {\n\n public static void main(String[] args) {\n \/\/ v1\u662f\u6307\u4e0a\u5b57\u7b26\u4e32\u5bf9\u8c61\uff1bString\n String v1 = new String("wupeiqi");\n String res = v1.toUpperCase();\n System.out.println(res);\n\n \/\/ v2\u672c\u8d28\u662f\u5b57\u7b26\u4e32\u5bf9\u8c61\uff1bObject\n Object v2 = new String("wupeiqi");\n String data = (String)v2;\n }\n}<\/code><\/pre>\nimport java.util.Arrays;\n\npublic class Hello {\n\n public static void func(Object v1) {\n \/\/ System.out.println(v1);\n \/\/ System.out.println(v1.getClass());\n if (v1 instanceof Integer) {\n System.out.println("\u6574\u578b");\n } else if (v1 instanceof String) {\n System.out.println("\u5b57\u7b26\u4e32\u7c7b\u578b");\n } else {\n System.out.println("\u672a\u77e5\u7c7b\u578b");\n }\n }\n\n public static void main(String[] args) {\n func(123);\n func("123");\n }\n}<\/code><\/pre>\n- \n
- Java\u4e2d\u6240\u6709\u7684\u7c7b\u90fd\u7ee7\u627fObject\uff0cObject\u4ee3\u6307\u6240\u6709\u7684\u7c7b\u578b\u3002<\/li>\n
- \u81ea\u5df1\u521b\u5efa\u5173\u7cfb
\n![\"image-20220127224643681\"](\"https:\/\/lemon-guess.oss-cn-hangzhou.aliyuncs.com\/img\/image-20220127224643681.png\")
<\/li>\n<\/ul>\nArrayList v1 = new ArrayList();\nLinkedList v2 = new LinkedList();<\/code><\/pre>\nList v1 = new ArrayList();\nList v2 = new LinkedList();<\/code><\/pre>\nObject v1 = new ArrayList();\nObject v2 = new LinkedList();<\/code><\/pre>\n1.\u5e38\u89c1\u6570\u636e\u7c7b\u578b<\/h2>\n
1.1 List\u7cfb\u5217<\/h3>\n
\n
\u7c7b\u4f3c\u4e8ePython\u4e2d\u7684\u5217\u8868\u3002<\/p>\n<\/blockquote>\n
List\u662f\u4e00\u4e2a\u63a5\u53e3\uff0c\u63a5\u53e3\u4e0b\u9762\u6709\u4e24\u4e2a\u5e38\u89c1\u7684\u7c7b\u578b\uff08\u76ee\u7684\u662f\u53ef\u4ee5\u5b58\u653e\u52a8\u6001\u7684\u591a\u4e2a\u6570\u636e\uff09<\/p>\n
- \n
- ArrayList\uff0c\u8fde\u7eed\u7684\u5185\u5b58\u5730\u5740\u7684\u5b58\u50a8\uff08\u5185\u90e8\u81ea\u52a8\u6269\u5bb9\uff09\u3002 -> Python\u5217\u8868\u7684\u7279\u70b9<\/li>\n
- LinkedList\uff0c\u5e95\u5c42\u57fa\u4e8e\u94fe\u8868\u5b9e\u73b0\uff08\u81ea\u884c\u8f66\u94fe\u6761\uff09\u3002 -> Python\u5217\u8868\u7684\u7279\u70b9<\/li>\n<\/ul>\n
ArrayList v1 = new ArrayList();\nv1.add("\u6b66\u6c9b\u9f50");\nv1.add("\u9ebb\u5b50");<\/code><\/pre>\nLinkedList v1 = new LinkedList();\nv1.add("\u6b66\u6c9b\u9f50");\nv1.add("\u9ebb\u5b50");<\/code><\/pre>\nJava\u4e2d\u63a5\u53e3\uff0c\u662f\u7528\u6765\u7ea6\u675f\u5b9e\u73b0\u4ed6\u7684\u7c7b\uff0c\u7ea6\u675f\u4ed6\u91cc\u9762\u7684\u6210\u5458\u5fc5\u987b\u6709xx\u3002<\/p>\n
interface List{\n public void add(Object data); \/\/ \u63a5\u53e3\u4e2d\u7684\u65b9\u6cd5\uff0c\u4e0d\u5199\u5177\u4f53\u7684\u5b9e\u73b0\uff0c\u53ea\u7528\u4e8e\u7ea6\u675f\u3002\n}\n\n\/\/ \u7c7bArrayList\u5b9e\u73b0\u4e86\u63a5\u53e3List\uff0c\u6b64\u65f6\u8fd9\u4e2a\u7c7b\u5c31\u5fc5\u987b\u6709\u4e00\u4e2aadd\u65b9\u6cd5\u3002\nclass ArrayList implements List{\n public void add(Object data){\n \/\/ \u5c06\u6570\u636edata\u6309\u7167\u8fde\u7eed\u5b58\u50a8\u7684\u65b9\u6cd5\u653e\u5728\u5185\u5b58\u3002\n \/\/ ..\n }\n}\n\n\/\/ \u7c7bLinkedList\u5b9e\u73b0\u4e86\u63a5\u53e3List\uff0c\u6b64\u65f6\u8fd9\u4e2a\u7c7b\u5c31\u5fc5\u987b\u6709\u4e00\u4e2aadd\u65b9\u6cd5\u3002\nclass LinkedList implements List{\n public void add(Object data){\n \/\/ \u5c06\u6570\u636edata\u6309\u7167\u94fe\u8868\u7684\u5f62\u5f0f\u5b58\u50a8\n \/\/ ..\n }\n}<\/code><\/pre>\nList v1 = new ArrayList();\nv1.add("\u6b66\u6c9b\u9f50");\nv1.add("\u9ebb\u5b50");<\/code><\/pre>\nList v1 = new LinkedList();\nv1.add("\u6b66\u6c9b\u9f50");\nv1.add("\u9ebb\u5b50");<\/code><\/pre>\nArrayList\u793a\u4f8b\uff1a<\/strong><\/p>\n
import java.util.ArrayList;\nimport java.util.Arrays;\n\npublic class Hello {\n\n public static void main(String[] args) {\n\n \/\/ ArrayList\uff0c\u9ed8\u8ba4\u5185\u90e8\u5b58\u653e\u7684\u662f\u6df7\u5408\u6570\u636e\u7c7b\u578b\u3002\n\n \/\/ ArrayList<String> data = new ArrayList<String>();\n \/\/ ArrayList<Object> data = new ArrayList<Object>();\n\n ArrayList data = new ArrayList();\n data.add("\u6b66\u6c9b\u9f50");\n data.add("alex");\n data.add(666);\n data.add("tony");\n\n String value = data.get(1);\n value.length\n\n \/\/ String value = (String) data.get(1);\n Object temp = data.get(1);\n String value = (String) temp; \/\/ \u8f6c\u5316\u53ef\u8f6c\u6362\u7684\u6570\u636e\n\n System.out.println(value);\n\n int xo = (int) data.get(2);\n System.out.println(xo);\n\n data.set(0, "\u54c8\u54c8\u54c8\u54c8");\n System.out.println(data);\n\n data.remove("eric");\n data.remove(0);\n System.out.println(data);\n\n int size = data.size();\n System.out.println(size);\n\n boolean exists = data.contains("\u6b66\u6c9b\u9f50");\n System.out.println(exists);\n\n for (Object item : data) {\n System.out.println(item);\n }\n\n for (int i = 0; i < data.size(); i++) {\n Object item = data.get(i);\n System.out.println(item);\n }\n }\n}<\/code><\/pre>\nLinkedList\u793a\u4f8b\uff1a<\/strong><\/p>\n
import java.util.LinkedList;\n\npublic class Hello {\n\n public static void main(String[] args) {\n LinkedList<Integer> v1 = new LinkedList<Integer>();\n v1.add(11);\n v1.add(22);\n\n LinkedList<Object> v2 = new LinkedList<Object>();\n v2.add("\u6709\u962a\u6df1\u96ea");\n v2.add("\u5927\u6865\u672a\u4e45");\n v2.add(666);\n v2.add(123);\n\n \/\/v2.remove(1);\n \/\/v2.remove("\u8def\u98de");\n\n v2.set(2, "\u82cd\u8001\u5e08");\n v2.push("\u54c8\u54c8\u54c8");\n \/\/ v2.addFirst(11);\n\n for (int i = 0; i < v2.size(); i++) {\n Object item = v2.get(i);\n System.out.println(item);\n }\n\n for (Object item : v2) {\n System.out.println(item);\n }\n }\n}<\/code><\/pre>\n\u5173\u4e8e\u8fed\u4ee3\u5668\uff1a<\/strong><\/p>\n
import java.util.*;\n\npublic class Hello {\n\n public static void main(String[] args) {\n\n ArrayList s1 = new ArrayList();\n s1.add("P\u7ad9");\n s1.add("B\u7ad9");\n s1.add("A\u7ad9");\n\n Iterator it = s1.iterator(); \/\/ \u8fed\u4ee3\u5668\n while (it.hasNext()) {\n String item = (String) it.next();\n System.out.println(item);\n }\n }\n}<\/code><\/pre>\n![\"image-20220208160404756\"](\"https:\/\/lemon-guess.oss-cn-hangzhou.aliyuncs.com\/img\/image-20220208160404756.png\")
<\/p>\n1.2 Set\u7cfb\u5217<\/h3>\n
Set\u662f\u4e00\u4e2a\u63a5\u53e3<\/strong>\uff0c\u5e38\u89c1\u5b9e\u73b0\u8fd9\u4e2a\u63a5\u53e3\u7684\u6709\u4e24\u4e2a\u7c7b\uff0c\u7528\u4e8e\u5b9e\u73b0\u4e0d\u91cd\u590d\u7684\u591a\u5143\u7d20\u96c6\u5408\u3002<\/p>\n
- \n
- HashSet\uff0c\u53bb\u91cd\uff0c\u65e0\u5e8f\u3002<\/li>\n
- TreeSet\uff0c\u53bb\u91cd\uff0c\u5185\u90e8\u9ed8\u8ba4\u6392\u5e8f\uff08ascii\u3001unicode\uff09\u3010\u4e0d\u540c\u7684\u6570\u636e\u7c7b\u578b\uff0c\u65e0\u6cd5\u8fdb\u884c\u6bd4\u8f83\u3011\u3002<\/li>\n<\/ul>\n
import java.util.*;\n\npublic class Hello {\n\n public static void main(String[] args) {\n \/\/ HashSet s1 = new HashSet();\n \/\/ Set s1 = new HashSet();\n \/\/ HashSet<String> s1 = new HashSet<String>();\n HashSet s1 = new HashSet();\n s1.add("P\u7ad9");\n s1.add("B\u7ad9");\n s1.add("A\u7ad9");\n s1.add("P\u7ad9");\n s1.add(666);\n System.out.println(s1); \/\/ [B\u7ad9, A\u7ad9, P\u7ad9,666]\n\n \/\/ s2 = {"\u4e1c\u4eac\u70ed","\u4e1c\u5317\u70ed","\u5357\u4eac\u70ed"}\n HashSet s2 = new HashSet(){\n {\n add("\u4e1c\u4eac\u70ed");\n add("\u4e1c\u5317\u70ed");\n add("\u5357\u4eac\u70ed");\n }\n };\n System.out.println(s2); \/\/ [B\u7ad9, A\u7ad9, P\u7ad9]\n\n \/\/ Set s2 = new TreeSet();\n \/\/ TreeSet<String> s2 = new TreeSet<String>();\n TreeSet s3 = new TreeSet();\n s3.add("P\u7ad9");\n s3.add("B\u7ad9");\n s3.add("A\u7ad9");\n s3.add("P\u7ad9");\n \/\/ s3.add(666); \/\/\u4e0d\u53ef\u4ee5\n\n System.out.println(s3); \/\/ [B\u7ad9, A\u7ad9, P\u7ad9]\n\n TreeSet s4 = new TreeSet(){\n {\n add("P\u7ad9");\n add("B\u7ad9");\n add("A\u7ad9");\n add("P\u7ad9");\n }\n };\n System.out.println(s4); \/\/ [B\u7ad9, A\u7ad9, P\u7ad9]\n\n }\n}<\/code><\/pre>\n\u5173\u4e8e\u4ea4\u5e76\u5dee\uff1a<\/p>\n
import java.util.*;\n\npublic class Hello {\n\n public static void main(String[] args) {\n \/\/ Set s1 = new HashSet();\n HashSet s1 = new HashSet();\n s1.add("P\u7ad9");\n s1.add("B\u7ad9");\n s1.add("A\u7ad9");\n s1.remove("P\u7ad9");\n System.out.println(s1); \/\/ [B\u7ad9, A\u7ad9, P\u7ad9]\n\n boolean exists = s1.contains("B\u7ad9");\n System.out.println(exists);\n\n HashSet s2 = new HashSet();\n s2.add(123);\n s2.add(456);\n\n HashSet v1 = new HashSet(); \/\/ \u7a7a \n v1.addAll(s1);\n v1.retainAll(s2); \/\/ \u4ea4\u96c6 & \n System.out.println(v1);\n\n HashSet v2 = new HashSet();\n v2.addAll(s1);\n v2.addAll(s2); \/\/ \u5e76\u96c6 |\n System.out.println(v2);\n\n HashSet v3 = new HashSet();\n v3.addAll(s1);\n v3.removeAll(s2); \/\/ \u5dee\u96c6 s1 - s2\n System.out.println(v3);\n\n HashSet v4 = new HashSet();\n v4.addAll(s2);\n v4.removeAll(s1); \/\/ \u5dee\u96c6 s2 - s1\n System.out.println(v4);\n }\n}<\/code><\/pre>\n\u5173\u4e8e\u5faa\u73af\u83b7\u53d6\uff1a<\/p>\n
import java.util.*;\n\npublic class Hello {\n\n public static void main(String[] args) {\n\n TreeSet s1 = new TreeSet();\n s1.add("P\u7ad9");\n s1.add("B\u7ad9");\n s1.add("A\u7ad9");\n\n for (Object item : s1) {\n System.out.println(item);\n }\n }\n}<\/code><\/pre>\n\u5173\u4e8e\u8fed\u4ee3\u5668\uff1a<\/p>\n
import java.util.*;\n\npublic class Hello {\n\n public static void main(String[] args) {\n\n TreeSet s1 = new TreeSet();\n s1.add("P\u7ad9");\n s1.add("B\u7ad9");\n s1.add("A\u7ad9");\n\n Iterator it = s1.iterator();\n while (it.hasNext()) {\n String item = (String) it.next();\n System.out.println(item);\n }\n }\n}<\/code><\/pre>\n![\"image-20220208160211442\"](\"https:\/\/lemon-guess.oss-cn-hangzhou.aliyuncs.com\/img\/image-20220208160211442.png\")
<\/p>\n1.3 Map\u7cfb\u5217<\/h3>\n
Map\u662f\u4e00\u4e2a\u63a5\u53e3\uff0c\u5e38\u89c1\u5b9e\u73b0\u8fd9\u4e2a\u63a5\u53e3\u7684\u6709\u4e24\u4e2a\u7c7b\uff0c\u7528\u4e8e\u5b58\u50a8\u952e\u503c\u5bf9\u3002<\/p>\n
- \n
- \n
HashMap\uff0c\u65e0\u5e8f\u3002<\/p>\n<\/li>\n
- \n
TreeMap\uff0c\u9ed8\u8ba4\u6839\u636ekey\u6392\u5e8f\u3002\uff08\u5e38\u7528\uff09<\/p>\n
\u5728Python\u4e2d\u9700\u8981\u81ea\u5df1\u5904\u7406key\u6392\u5e8f\u7684\u95ee\u9898\u3002\nv4 = {\n\"aid\":123,\n\"xx\":999,\n\"wid\":888\n}\n\n# 1.\u6839\u636ekey\u8fdb\u884c\u6392\u5e8f\n# data = [\"{}={}\".format(key,v4[key]) for key in sorted(v4.keys())]\n\n# 2.\u518d\u8fdb\u884c\u62fc\u63a5\n# result = \"&\".join(data)\n\nresult = \"&\".join([\"{}={}\".format(key,v4[key]) for key in sorted(v4.keys())])<\/code><\/pre>\n<\/li>\n<\/ul>\nimport java.util.*;\n\npublic class Hello {\n\n public static void main(String[] args) {\n HashMap h1 = new HashMap();\n h1.put("name","alex");\n h1.put("age",18);\n h1.put("hobby","\u7537");\n System.out.println(h1); \/\/ {gender=\u7537, name=alex, age=18}\n\n HashMap<String,String> h2 = new HashMap<String,String>();\n h2.put("name","alex");\n h2.put("age","18");\n h2.put("hobby","\u7537");\n System.out.println(h2); \/\/ {gender=\u7537, name=alex, age=18}\n\n HashMap<String,String> h3 = new HashMap<String,String>(){\n {\n put("name","alex");\n put("age","18");\n put("hobby","\u7537");\n }\n };\n System.out.println(h3); \/\/ {gender=\u7537, name=alex, age=18}\n }\n}<\/code><\/pre>\nimport java.util.*;\n\npublic class Hello {\n\n public static void main(String[] args) {\n TreeMap h1 = new TreeMap(); \/\/ \u6539\u4e3a\u4e86TreeMap\n h1.put("name","alex");\n h1.put("age",18);\n h1.put("hobby","\u7537");\n System.out.println(h1); \/\/ {age=18, hobby=\u7537, name=alex}\n\n TreeMap<String,String> h2 = new TreeMap<String,String>();\n h2.put("name","alex");\n h2.put("age","18");\n h2.put("hobby","\u7537");\n System.out.println(h2); \/\/ {age=18, hobby=\u7537, name=alex}\n\n TreeMap<String,String> h3 = new TreeMap<String,String>(){\n {\n put("name","alex");\n put("age","18");\n put("hobby","\u7537");\n }\n };\n System.out.println(h3); \/\/ {age=18, hobby=\u7537, name=alex}\n\n Map h4 = new TreeMap();\n h4.put("name","alex");\n h4.put("age",18);\n h4.put("hobby","\u7537");\n System.out.println(h4); \/\/ {age=18, hobby=\u7537, name=alex}\n }\n}<\/code><\/pre>\n\u5e38\u89c1\u64cd\u4f5c\uff1a<\/p>\n
import java.util.*;\n\npublic class Hello {\n\n public static void main(String[] args) {\n TreeMap h1 = new TreeMap(); \/\/ \u6539\u4e3a\u4e86TreeMap\n h1.put("name", "alex");\n h1.put("age", "18");\n h1.put("hobby", "\u7537");\n h1.put("hobby", "\u5973\u4eba");\n\n h1.remove("age");\n int size = h1.size();\n\n Object value = h1.get("name"); \/\/ \u4e0d\u5b58\u5728\uff0c\u8fd4\u56denull\n System.out.println(value);\n\n boolean existsKey = h1.containsKey("age");\n boolean existsValue = h1.containsValue("alex");\n\n h1.replace("name", "\u674e\u6770");\n System.out.println(h1);\n\n \/\/ \u5faa\u73af: \u793a\u4f8b1\n \/\/ { ("name", "alex")\uff0c("age", "18"), }\n Set<Map.Entry<String, String>> s1 = h1.entrySet();\n Iterator it1 = s1.iterator();\n while (it1.hasNext()) {\n \/\/ ("name", "alex")\n Map.Entry<String, String> entry = (Map.Entry<String, String>) it1.next();\n String k = (String) entry.getKey();\n String v = (String) entry.getValue();\n }\n\n \/\/ \u5faa\u73af: \u793a\u4f8b2\n Set s2 = h1.entrySet();\n Iterator it2 = s2.iterator();\n while (it2.hasNext()) {\n Map.Entry entry = (Map.Entry) it2.next();\n String k = (String) entry.getKey();\n String v = (String) entry.getValue();\n }\n\n \/\/ \u5faa\u73af: \u793a\u4f8b3\n TreeMap<String, String> h2 = new TreeMap<String, String>(); \/\/ \u6539\u4e3a\u4e86TreeMap\n h2.put("name", "alex");\n h2.put("age", "18");\n for (Map.Entry<String, String> entry : h2.entrySet()) {\n String k = entry.getKey();\n String v = entry.getValue();\n }\n\n \/\/ \u5faa\u73af: \u793a\u4f8b4\n TreeMap h3 = new TreeMap(); \/\/ \u6539\u4e3a\u4e86TreeMap\n h3.put("name", "alex");\n h3.put("age", 18);\n\n for (Object entry : h3.entrySet()) {\n Map.Entry<String, Object> entryMap = (Map.Entry<String, Object>) entry;\n String k = entryMap.getKey();\n Object v = entryMap.getValue(); \/\/ 18 "alex"\n\n if (v instanceof Integer) {\n System.out.println("\u6570\u5b57\uff1a" + Integer.toString((Integer) v));\n } else if (v instanceof String) {\n System.out.println("\u5b57\u7b26\u4e32\uff1a" + (String) v);\n } else {\n System.out.println("\u672a\u77e5\u7c7b\u578b\uff1a" + v.toString());\n }\n }\n }\n}<\/code><\/pre>\n![\"image-20220208151234641\"](\"https:\/\/lemon-guess.oss-cn-hangzhou.aliyuncs.com\/img\/image-20220208151234641.png\")
<\/p>\n![\"image-20210928193550689\"](\"https:\/\/lemon-guess.oss-cn-hangzhou.aliyuncs.com\/img\/image-20210928193550689-4303181.png\")
<\/p>\n![\"image-20210928193623922\"](\"https:\/\/lemon-guess.oss-cn-hangzhou.aliyuncs.com\/img\/image-20210928193623922-4303181.png\")
<\/p>\n2.\u9762\u5411\u5bf9\u8c61\u76f8\u5173<\/h2>\n
2.1 \u7c7b\u548c\u5bf9\u8c61<\/h3>\n
class Person {\n \/\/ \u5b9e\u4f8b\u53d8\u91cf\n public String name;\n public Integer age;\n\n \/\/ \u6784\u9020\u65b9\u6cd51\n public Person() {\n this.name = "Eric";\n this.age = 99999;\n }\n}\n\nPerson obj = new Person();<\/code><\/pre>\nclass Person:\n def __init__(self):\n self.name = "eric"\n self.age = 999999\n\nobj = Person()<\/code><\/pre>\nclass Person {\n\n \/\/ \u5b9e\u4f8b\u53d8\u91cf\n public String name;\n public Integer age;\n public String email;\n\n \/\/ \u6784\u9020\u65b9\u6cd51\n public Person() {\n this.name = "Eric";\n this.age = 99999;\n }\n\n \/\/ \u6784\u9020\u65b9\u6cd52\n public Person(String name, Integer age) {\n this.name = name;\n this.age = age;\n this.email = "xxx@live.com";\n }\n\n \/\/ \u6784\u9020\u65b9\u6cd53\n public Person(String name, String email) {\n this.name = name;\n this.age = 83;\n this.email = email;\n }\n}\n\nPerson obj = new Person("wupeiqi",11);<\/code><\/pre>\nclass Person {\n\n \/\/ \u5b9e\u4f8b\u53d8\u91cf\n public String name;\n public Integer age;\n public String email;\n\n \/\/ \u6784\u9020\u65b9\u6cd51\n public Person() {\n this.name = "Eric";\n this.age = 99999;\n }\n\n \/\/ \u6784\u9020\u65b9\u6cd52\n public Person(String name, Integer age) {\n this.name = name;\n this.age = age;\n this.email = "xxx@live.com";\n }\n\n \/\/ \u6784\u9020\u65b9\u6cd53\n public Person(String name, String email) {\n this.name = name;\n this.age = 83;\n this.email = email;\n }\n\n \/\/ \u5b9a\u4e49\u65b9\u6cd5\uff08\u91cd\u8f7d\uff09\n public void doSomething() {\n System.out.println(this.name);\n }\n\n \/\/ \u5b9a\u4e49\u65b9\u6cd5\uff08\u91cd\u8f7d\uff09\n public void doSomething(String prev) {\n String text = String.format("%s-%s", prev, this.name);\n System.out.println(text);\n }\n\n}\n\npublic class Hello {\n\n public static void main(String[] args) {\n\n \/\/ \u5b9e\u4f8b\u5316\u5bf9\u8c61\u65f6\uff0c\u4f53\u73b0\u7684\u4e3b\u8981\u662f\u5c01\u88c5\u3002\n Person p1 = new Person();\n Person p2 = new Person("alex", 73);\n Person p3 = new Person("tony", "alex@sb.com");\n\n p1.doSomething();\n p1.doSomething("\u4f60\u597d\u5440\uff0c");\n\n p2.doSomething();\n p2.doSomething("\u4f60\u597d\u5440\uff0c");\n\n p3.doSomething();\n p3.doSomething("\u4f60\u597d\u5440\uff0c");\n }\n}<\/code><\/pre>\n2.3 \u9759\u6001\u6210\u5458<\/h3>\n
class Foo:\n v1 = "\u6b66\u6c9b\u9f50" # \u9759\u6001\u53d8\u91cf\uff08\u5c5e\u4e8e\u7c7b\uff0c\u4e0e\u5bf9\u8c61\u65e0\u5173\uff09\n\n def __init__(self):\n self.name = "alex" # \u5b9e\u4f8b\u53d8\u91cf\uff0c\u5c5e\u4e8e\u5bf9\u8c61\n\nprint(Foo.v1)\n\n# 1.\u521b\u5efa\u7a7a\u7684\u533a\u57df\n# 2.\u81ea\u52a8\u6267\u884c\u6784\u9020\u65b9\u6cd5 __init__\nobj = Foo()\nobj.v1<\/code><\/pre>\n![\"image-20220208221733720\"](\"https:\/\/lemon-guess.oss-cn-hangzhou.aliyuncs.com\/img\/image-20220208221733720.png\")
<\/p>\nclass Person {\n \/\/ \u9759\u6001\u53d8\u91cf\n public static String city = "\u5317\u4eac";\n\n \/\/ \u5b9e\u4f8b\u53d8\u91cf\n public String name;\n public Integer age;\n\n \/\/ \u6784\u9020\u65b9\u6cd51\n public Person() {\n this.name = "Eric";\n this.age = 99999;\n }\n\n \/\/ \u7ed1\u5b9a\u65b9\u6cd5\n public void showInfo(){\n System.out.println("\u54c8\u54c8\u54c8\u54c8");\n }\n\n \/\/ \u9759\u6001\u65b9\u6cd5\n public static void showData(){\n System.out.println("\u54c8\u54c8\u54c8\u54c8");\n }\n}\n\nPerson.city;\nPerson.showData();\n\nPerson obj = new Person();\nobj.name;\nobj.age;\nobj.showInfo();<\/code><\/pre>\n\u672c\u8d28\uff1a\u9759\u6001\u5c5e\u4e8e\u7c7b\uff1b\u975e\u9759\u6001\u5c5e\u4e8e\u5bf9\u8c61\u3002<\/p>\n
2.3 \u7ee7\u627f<\/h3>\n
Java\u4e2d\u7684\u7ee7\u627f\uff0c\u53ea\u652f\u6301\u5355\u7ee7\u627f\uff0c\u4e0d\u652f\u6301\u591a\u7ee7\u627f\uff0c\u4f46\u652f\u6301\u5b9e\u73b0\u591a\u4e2a\u63a5\u53e3\u3002<\/p>\n
class Base{\n ...\n}\n\nclass Foo{\n ...\n}\n\nclass Son(Base){\n\n}<\/code><\/pre>\ninterface Base{\n public void add();\n}\n\ninterface Foo{\n public void plus();\n}\n\nclass Son implements Base,Foo {\n public void add(){\n\n }\n public void plus(){\n\n }\n}<\/code><\/pre>\nPython\u4e2d\u4e4b\u548c\u591a\u7ee7\u627f\u3002<\/p>\n
class Foo(Base,Bar):\n pass\n\nclass Foo(IBase,IBar):\n pass<\/code><\/pre>\nclass Base {\n public String email;\n\n public Base(String email) {\n this.email = email;\n }\n\n public String getSubInfo() {\n return String.format("%s", this.email);\n }\n}\n\n\/\/ Base obj1 = new Base("xx");\n\/\/ obj1.email; \/\/ "xx"\n\/\/ obj1.getSubInfo();\n\nclass Person extends Base {\n\n public String name;\n public Integer age;\n\n public Person(String name, Integer age, String email) {\n super(email);\/\/ \u6267\u884c\u7236\u7c7b\u7684\u6784\u9020\u65b9\u6cd5\n\n this.name = name;\n this.age = age;\n }\n\n public String getInfo(String v1) {\n return String.format("%s-%d-%s", this.name, this.age, this.email);\n }\n}\n\n\/\/ obj2 ==> email="xxx@live.com" name="wupeiqi" age=19\nPerson obj2 = new Person("wupeiqi",19,"xxx@live.com");\n\n\/\/ obj2.name;\n\/\/ obj2.age;\n\/\/ obj2.email;\n\n\/\/ obj2.getInfo("xxx");\n\/\/ obj2.getSubInfo();<\/code><\/pre>\n\u7528\u7236\u7c7b\u6cdb\u6307\u6240\u6709\u7684\u5b50\u7c7b\u3002<\/p>\n
class Base {\n\n}\n\nclass Person extends Base {\n\n}\n\nPerson v1 = new Person(); \/\/ v1\u662fPerson\u7c7b\u578b\u7684\u5bf9\u8c61\nBase v2 = new Person(); \/\/ v2\u662fPerson\u7c7b\u578b\u7684\u5bf9\u8c61<\/code><\/pre>\nclass Base {\n public void show() {\n System.out.println("111");\n }\n}\n\nclass Person extends Base {\n public void show() {\n System.out.println("222");\n }\n}\n\nPerson v1 = new Person();\nv1.show(); \/\/ 222\n\nBase v2 = new Base();\nv2.show(); \/\/ 111\n\nBase v3 = new Person();\nv3.show(); \/\/ 222<\/code><\/pre>\nclass Base {\n public String email;\n\n public Base(String email) {\n this.email = email;\n }\n\n public void getSubInfo() {\n System.out.println("111");\n }\n}\n\n\/\/ Person\u7c7b\u7ee7\u627fBase\u7c7b\nclass Person extends Base {\n\n public String name;\n\n public Person(String name, Integer age, String email) {\n super(email);\/\/ \u6267\u884c\u7236\u7c7b\u7684\u6784\u9020\u65b9\u6cd5\n this.name = name;\n }\n\n public void getSubInfo() {\n System.out.println("222");\n }\n}\n\npublic class Hello {\n\n public static void handler(Base v1){\n v1.getSubInfo();\n }\n\n \/\/ \u4e3b\u51fd\u6570\n public static void main(String[] args) {\n Person obj1 = new Person("wupeiqi",19,"xxx@live.com");\n handler(obj1); \/\/ 222\n\n Base obj2 = new Base("xxx@live.com");\n handler(obj2); \/\/ 111\n\n Base obj3 = new Person("wupeiqi",19,"xxx@live.com");\n handler(obj3); \/\/ 222\n }\n\n}<\/code><\/pre>\n2.4 \u63a5\u53e3<\/h3>\n
\u63a5\u53e3\uff1a<\/p>\n
- \n
- \u7ea6\u675f\uff0c\u5b9e\u73b0\u4ed6\u7684\u7c7b\u3002<\/li>\n
- \u6cdb\u6307
\u5b9e\u73b0<\/code> \u4ed6\u4e86\u7c7b\u3002<\/li>\n<\/ul>\ninterface IMessage {\n public void send();\n}\n\n\/\/ Wechat\u7c7b"\u5b9e\u73b0"\u4e86Imessage\u63a5\u53e3\nclass Wechat implements IMessage {\n public void send() {\n System.out.println("\u53d1\u9001\u5fae\u4fe1");\n }\n}\n\nclass DingDing implements IMessage {\n public void send() {\n System.out.println("\u53d1\u9001\u9489\u9489");\n }\n}\n\nclass Sms implements IMessage {\n public void send() {\n System.out.println("\u53d1\u9001\u77ed\u4fe1");\n }\n}\n\nIMessage v1 = new Wechat();\n<\/code><\/pre>\npublic class Hello {\n public static void handler(IMessage v1){\n v1.send();\n }\n\n \/\/ \u4e3b\u51fd\u6570\n public static void main(String[] args) {\n DingDing v1 = new DingDing();\n handler(v1);\n }\n}<\/code><\/pre>\n\u5728Java\u4e2d\uff1a\u4e0d\u652f\u6301\u540c\u65f6\u7ee7\u627f\u591a\u4e2a\u7c7b\uff1b\u652f\u6301\u5b9e\u73b0\u591a\u4e2a\u63a5\u53e3\u3002<\/p>\n
interface IPerson {\n public void f1();\n\n public void f1(int age);\n\n public void f2(String info);\n}\n\ninterface IUser {\n public String f3(int num);\n}\n\nclass Base {\n public String name;\n public Integer age;\n public String email;\n\n public Base(String name, Integer age, String email) {\n this.name = name;\n this.age = age;\n this.email = email;\n }\n\n public String getSubInfo() {\n return String.format("%s", this.email);\n }\n}\n\nclass Person extends Base implements IUser, IPerson {\n\n public Person(String name, Integer age, String email) {\n super(name, age, email);\n }\n\n public String getInfo() {\n return String.format("%s-%d-%s", this.name, this.age, this.email);\n }\n\n public void f1() {\n System.out.println("F1,\u65e0\u53c2\u6570");\n }\n\n public void f1(int age) {\n System.out.println("F1,age\u53c2\u6570");\n }\n\n public void f2(String info) {\n System.out.println("F2");\n }\n\n public String f3(int num) {\n return "\u54c8\u54c8\u54c8";\n }\n}\n\npublic class Hello {\n\n public static void main(String[] args) {\n Person p = new Person("\u65e5\u5929", 83, "ritian@live.com");\n p.f1();\n }\n}<\/code><\/pre>\n\u5047\u8bbe\u6211\u73b0\u5728\u5728\u8fdb\u884c\u9006\u5411\uff0c\u62ff\u5230apk\uff0c\u5173\u4e8e\u5173\u952e\u5b57\u53bb\u641c\u7d22\uff1af2 \uff0c\u5b9a\u4f4d\u5230\u4e00\u4e2a\u63a5\u53e3\u4e86\u3002<\/p>\n
interface IPerson {\n public void f1();\n\n public void f1(int age);\n\n public void f2(String info);\n}<\/code><\/pre>\n\u63a5\u4e0b\u6765\uff0c\u4f60\u5c31\u5e94\u8be5\u53bb\u770b\u90fd\u6709\u54ea\u4e9b\u7c7b \u5b9e\u73b0\u4e86 IPerson \u63a5\u53e3\u3002<\/p>\n
- \n
- \u53ea\u67091\u4e2a\u7c7b\u5b9e\u73b0 IPerson\u3002 <\/li>\n
- \u591a\u7c7b\u7c7b\u5b9e\u73b0 IPerson \u63a5\u53e3\uff0c\u7b5b\u9009\u5230\u5e95\u662f\u90a3\u4e2a\u7c7b\uff1f<\/li>\n<\/ul>\n
2.5 \u62bd\u8c61<\/h3>\n
\/\/ \u62bd\u8c61\u7c7b\nabstract class Base {\n\n \/\/ \u62bd\u8c61\u65b9\u6cd5\uff08\u7ea6\u675f\u5b50\u7c7b\u4e2d\u5fc5\u987b\u6709\u8fd9\u4e2a\u65b9\u6cd5\uff09\n public abstract void play(String name);\n\n \/\/ \u666e\u901a\u65b9\u6cd5\n public void stop() {\n System.out.println("Stop");\n }\n}\n\nclass Son extends Base{\n public void play(String name){\n \/\/ ...\n }\n}\n\nSon obj = new Son();\nobj.stop();\nobj.play();\n\nBase obj1 = new Son();<\/code><\/pre>\n\u6ce8\u610f\uff1a\u4e5f\u53ef\u4ee5\u6cdb\u6307\u4ed6\u7684\u5b50\u7c7b\u3002<\/p>\n
3.\u5305\u6982\u5ff5<\/h2>\n
src\n\u251c\u2500\u2500 Hello.java\n\u2514\u2500\u2500 utils\n \u2514\u2500\u2500 Helper.java<\/code><\/pre>\n\/\/ hello.java\nimport utils.Helper;\n\npublic class Hello {\n\n public static void main(String[] args) {\n String data = Helper.getInfo();\n System.out.println(data);\n }\n}\n<\/code><\/pre>\n\/\/ helper.java\npackage utils;\n\npublic class Helper {\n public static String getInfo() {\n return "\u54c8\u54c8\u54c8";\n }\n}<\/code><\/pre>\n\u7c7b\u7684\u4fee\u9970\u7b26\uff1a<\/strong><\/p>\n
- \n
- public\uff0c\u516c\u5171\uff08\u4efb\u4f55\u4eba\u90fd\u80fd\u8c03\u7528\u5305\u4e2d\u7684\u7c7b\uff09\u3002<\/li>\n
- default\uff0c\u53ea\u80fd\u5728\u5f53\u524d\u5305\u4e2d\u88ab\u8c03\u7528\u3002<\/li>\n<\/ul>\n
\u7c7b\u6210\u5458\u4fee\u9970\u7b26\uff1a<\/strong><\/p>\n
- \n
- public\uff0c\u516c\u5171\uff0c\u6240\u6709\u7684\u53ea\u8981\u6709\u6743\u9650\u8bbf\u95ee\u7c7b\uff0c\u7c7b\u4e2d\u7684\u6210\u5458\u90fd\u53ef\u4ee5\u8bbf\u95ee\u5230\u3002<\/li>\n
- private\uff0c\u79c1\u6709\uff0c\u53ea\u5141\u8bb8\u81ea\u5df1\u7c7b\u8c03\u7528\u3002<\/li>\n
- protected\uff0c\u540c\u4e00\u4e2a\u5305 \u6216 \u5b50\u7c7b\u53ef\u4ee5\u8bbf\u95ee\uff08\u5373\u4f7f\u6ca1\u6709\u5728\u540c\u4e00\u4e2a\u5305\u5185\uff0c\u4e5f\u53ef\u4ee5\u8bbf\u95ee\u7236\u7c7b\u4e2d\u7684\u53d7\u4fdd\u62a4\u6210\u5458\uff09\u3002<\/li>\n
- default\uff0c\u53ea\u80fd\u5728\u540c\u4e00\u4e2a\u5305\u5185\u8bbf\u95ee\u3002<\/li>\n<\/ul>\n
\u76ee\u7684\uff1a\u901a\u8fc7\u5173\u952e\u5b57\u8ba9\u8c03\u7528\u5173\u7cfb\u66f4\u52a0\u6e05\u6670\uff08\u4e0d\u8fc7\uff0c\u5f88\u591a\u9879\u76ee\u4e0d\u4f1a\u7528\u7684\u90a3\u4e48\u4e13\u4e1a\uff09\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"
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