如何检查输入是否为C中的数字? [英] how to check if the input is a number or not in C?

问题描述

在C的main函数中:

In the main function of C:

void main(int argc, char **argv)
{
   // do something here
}

在命令行中，我们将输入任意数字，例如1或2作为输入，但它会被视为argv参数的char数组，但如何确保输入是数字，以防人们输入 hello 或 c?

In the command line, we will type any number for example 1 or 2 as input, but it will be treated as char array for the parameter of argv, but how to make sure the input is a number, in case people typed hello or c?

推荐答案

另一种方法是使用 isdigit 函数.下面是它的代码:

Another way of doing it is by using isdigit function. Below is the code for it:

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#define MAXINPUT 100
int main()
{
    char input[MAXINPUT] = "";
    int length,i; 

    scanf ("%s", input);
    length = strlen (input);
    for (i=0;i<length; i++)
        if (!isdigit(input[i]))
        {
            printf ("Entered input is not a number\n");
            exit(1);
        }
    printf ("Given input is a number\n");
}

这篇关于如何检查输入是否为C中的数字?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！