int c = i++; // => c = i; i = i+1; // 先使用,后自增 System.out.println("c="+c+",i="+i); // => c = 12 i = 13 int d = ++i; // => i=i+1; d = i; // 先自增,后使用 System.out.println("d="+d+",i="+i); // => i = 14 d = 14
int num2 = 1; num2 = ++num2; System.out.println(num2); // 2 int c = i++;// 表达式的值 = 12 ; i=i+1 i=13; c = 表达式的值 c = 12 System.out.println("c=" + c + ",i=" + i); int d = ++i;// i=i+1 i=14; 表达式的值 = 14 ; c = 表达式的值 c = 14 System.out.println("d=" + d + ",i=" + i);
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classDemo { publicstaticvoidmain(String[] args) { int a = 0; //int sum = ++a; //前自增。 a = a+1 , sum = a int sum = a++; //后自增 sum = 0 , a = a+1 System.out.println("sum= "+ sum+ " a = "+ a); //1 } }