j02050606.java

来自「经典java教材《java完美经典》一书中源码的完全收集」· Java 代码 · 共 36 行

import java.lang.*;

class j02050606
{    
  public static void main(String para[])
  {  		
		int a = 0,sum = 0;	
		for( a=1 ; a<=5 ; a++ )
		{
    	sum = sum + a;  // sum += a; 也一样
    	System.out.println("1 +...+ "+ a +" = "+ sum);
    }    
    System.out.println("===========================");    
    a = 1;
    sum = 0;
    for( System.out.println("计算 1 +...+ 5") ; a<=5 ; /*无动作*/ )
    { 
      sum = sum + a;
      System.out.println("1 +...+ "+ a +" = "+ sum);
      a++;
    }    
    System.out.println("===========================");    
    a = 1;
    sum = 0;
    for( ; ; )
    { 
      sum = sum + a;
      System.out.println("1 +...+ "+ a +" = "+ sum);
      a++;
      if(a>5)
         break;
    }
  }
}