c - 警告 : implicit declaration of function 'strcmp'

Question

这个问题已经有答案了:

I get implicit declaration of function strncmp (2 个回答)

已关闭 3 年前。

创建一个简单的代码来扫描两个数字，询问用户是否想要将它们相加或相乘，然后执行运算并打印输出。

#include <stdio.h>
int main(){
int num1;
int num2;
char oper[] = "";
printf("Enter a number: ");
scanf("%d", &num1);
printf("Enter another number: ");
scanf("%d", &num2);
printf("Would you like to add or multiply these numbers? ");
scanf("%s", &oper);
if(strcmp(oper, "multiply") == 0){
    int prod = num1 * num2;
    printf("The product is %d", prod);
}
else if(strcmp(oper, "add") == 0){
    int sum = num1 + num2;
    printf("The sum is %d", sum);
}
else{
    printf("Why would you input something that you knew wouldn't work?");
}
return 0;
}

Answer 1

您正在使用 strcmp 函数而没有声明它们。您需要包含包含 strcmp 函数声明的头文件。

用途:

#include <string.h>