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package test; public class abc { public static void main(String[] arg) { int[][] xx=new int[3][]; xx[0]=new int[3]; xx[1]=new int[2]; xx[2]=new int[1]; for(int i=0;i<xx.length;++i) for(int j=0;j<xx[i].length;++j) xx[i][j]=j; for(int[] i1:xx) for(int j:i1) System.out.println(j); System.out.println(">>>>>>>>>>>"); int [][] x={{1,2,3},{1,2},{1}}; System.out.println(x[1][1]); } } |
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package test2_class; public class student { String sName; String sNumber; int sage; public String getsName() { return sName; } public void setsName(String sName) { this.sName = sName; } public String getsNumber() { return sNumber; } public void setsNumber(String sNumber) { this.sNumber = sNumber; } public int getSage() { return sage; } public void setSage(int sage) { this.sage = sage; } void eat() { System.out.println(sName+" have lunch"); } void sleep() { System.out.println(sName+" sleep"); } public boolean equals(Object obj) { student s=(student)obj; if(sName==s.sName&&sage==s.sage&&sNumber==s.sName) { return true; } return false; } public String toString() { return "name:"+sName+"\t"+"age:"+sage+"\t"+"number:"+sNumber; } } |
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package test2_class; public class Main { public static void main(String[] args) { student t=new student(); t.setsName("zhangsan"); t.setSage(15); t.setsNumber("2678"); System.out.println(t.getSage()); System.out.println(t.getSage()); System.out.println(t.getSage()); t.eat(); t.sleep(); if(t.equals(t)) System.out.println("equal"); System.out.println(t); } } |
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package string_practice; public class string_practice { public static void main(String[] args) { // TODO Auto-generated method stub String str3="HELLO"; String str4="HELLO"; String str1=new String("HELLO"); String str2=new String("HELLO"); if(str3==str4) { System.out.println("equals"); } if(str1.equals(str2)) { System.out.println("equals"); } Integer a = new Integer(1); } } |
类方法中不能访问非static变量.
导入的两个包有相同名的类，则不导入
final定义常量的关键