C 交换两个数字的程序-立地货

交换两个数字的C程序

在本例中，您将学习使用两种不同的技术在 C 编程中交换两个数字。

要理解此示例，您应该了解以下C 编程主题:

C 数据类型

C 编程运算符

C 输入输出(I/O)

使用临时变量交换数字

#include<stdio.h>
int main() {
  double first, second, temp;
  printf("Enter first number: ");
  scanf("%lf", &first);
  printf("Enter second number: ");
  scanf("%lf", &second);
  // value of first is assigned to temp
  temp = first;
  // value of second is assigned to first
  first = second;
  // value of temp (initial value of first) is assigned to second
  second = temp;
  // %.2lf displays number up to 2 decimal points
  printf("\nAfter swapping, first number = %.2lf\n", first);
  printf("After swapping, second number = %.2lf", second);
  return 0;
}

输出

Enter first number: 1.20
Enter second number: 2.45
After swapping, first number = 2.45
After swapping, second number = 1.20

在上面的程序中， temp 变量被赋值为 first 变量的值。

然后，将 first 变量的值分配给 second 变量。

最后， temp(保存了 first 的初始值)被分配给 second。这样就完成了交换过程。

不使用临时变量交换数字

#include <stdio.h>
int main() {
  double a, b;
  printf("Enter a: ");
  scanf("%lf", &a);
  printf("Enter b: ");
  scanf("%lf", &b);
  // swapping
  // a = (initial_a-initial_b)
  a = a-b;   
  // b = (initial_a-initial_b) + initial_b = initial_a
  b = a + b;
  // a = initial_a-(initial_a-initial_b) = initial_b
  a = b-a;
  // %.2lf displays numbers up to 2 decimal places
  printf("After swapping, a = %.2lf\n", a);
  printf("After swapping, b = %.2lf", b);
  return 0;
}

输出

Enter a: 10.25
Enter b:-12.5
After swapping, a =-12.50
After swapping, b = 10.25