关于for循环的一些总结

//这个程序用于测试一些简单的循环应用 
public class ForTest{ 
    public static void main(String[] args){ 
 
/*      //用for循环计算1~10的整数的和
        int j = 0;
        for(int i = 1; i <= 10; j += i++);
        System.out.println("1到10的和为" + j);
*/ 
 
/*      //用while循环计算1~10的整数的和
        int i = 0,j = 0;
        while(j < 10){
            i += ++j;
        }
        System.out.println("1到10的和为" + i);
*/ 
 
/*
        //1~100之间7的倍数有多少个？
        int sum = 1;
        while(sum * 7 <= 100){
            sum++;
        }
        System.out.println("1~100之间7的倍数有" + (sum - 1) +"个");
*/ 
 
/*
        //打印正直角三角
        for(int i = 1; i <=5; i++){
            for(int j = 1; j <= i; j++){
                System.out.print("*");      
            }
        System.out.println();
        }
*/ 
 
/*
        //打印倒三角三角
        for(int i = 1; i <=5; i++){
            for(int j = i; j <= 5; j++){
                System.out.print("*");      
            }
        System.out.println();
        }
*/ 
 
/*      //打印正等腰三角
        for(int i = 0; i < 4; i++){
            for(int j = -4; j <= 4; j++){                
                System.out.print(Math.abs(j) <= i ? '*' : ' ');      
            }
        System.out.println();
        }
*/ 
/*      //打印实心菱形
        for(int i = -4; i <= 4; i++){
            for(int j = -4; j <= 4; j++){                
                System.out.print(Math.abs(j) + Math.abs(i) <= 4 ? '*' : ' ');        
            }
        System.out.println();
        }
*/ 
 
/*      //打印空心菱形
        for(int i = -4; i <= 4; i++){
            for(int j = -4; j <= 4; j++){                
                System.out.print(Math.abs(j) + Math.abs(i) == 4 ? '*' : ' ');       
            }
        System.out.println();
        }
*/ 
/*      //一层循环一条print打印空心菱形
        for(int i = -4,j = -4; i <= 4; j++){             
            System.out.print(Math.abs(i) + j == 5 && (j = -5) != i++ ? "\n" : Math.abs(j) + Math.abs(i) == 4 ? '*' : ' ');  
        }
*/ 
         
/*      //打印九九乘法表
        for(int i = 1; i <= 9; i++){
            for(int j = 1; j <= i; j++){             
                System.out.print(j + "*" + i + "=" +  i * j + "\t");        
            }
        System.out.println();
        }
*/ 
        //一层循环一条print打印九九乘法表 
        for(int i = 1, j = 1; j <= 9; i++){ 
            System.out.print(i + "*" + j + "=" + i * j + (i == j && (i = 0) != j++ ? "\n" : "\t")); 
        } 
    } 
}  

转载于:https://www.cnblogs.com/xgwtzg/p/6140014.html