使用临时变量

以下实例演示了交换两个浮点数得值。

实例

#include <stdio.h>

int main()

{

double firstNumber, secondNumber, temporaryVariable;

printf("输入第壹个数字: ");

scanf("%lf", &firstNumber);

printf("输入第二个数字: ");

scanf("%lf",&secondNumber);

// 将第壹个数得值赋值给 temporaryVariable

temporaryVariable = firstNumber;

// 第二个数得值赋值给 firstNumber

firstNumber = secondNumber;

// 将 temporaryVariable 赋值给 secondNumber

secondNumber = temporaryVariable;

printf("\n交换后, firstNumber = %.2lf\n", firstNumber);

printf("交换后, secondNumber = %.2lf", secondNumber);

return 0;

}

运行结果：

输入第壹个数字: 1输入第二个数字: 2交换后, firstNumber = 2.00交换后, secondNumber = 1.00

不使用临时变量

不使用临时变量交换两个整数得值：

实例

#include <stdio.h>

int main() {

int a, b;

a = 11;

b = 99;

printf("交换之前 - \n a = %d, b = %d \n\n", a, b);

a = a + b; // ( 11 + 99 = 110) 此时 a 得变量为两数之和，b 未改变

b = a - b; // ( 110 - 99 = 11)

a = a - b; // ( 110 - 11 = 99)

printf("交换后 - \n a = %d, b = %d \n", a, b);

}

运行结果：

交换之前 - a = 11, b = 99 交换后 - a = 99, b = 11