Input %*s of c language tips

foreword

%*s is part of the format string used to skip a string during input without storing it into a variable. This is useful when dealing with input where certain parts need to be skipped.

main body

Specifically, %*s works as follows:

%*s: Indicates to ignore a string. * is used to specify an optional field width, but in this case the field width has no real effect.
s: The format specifier indicates to read a string.
Here is an example showing how to use %*s to skip strings in the input:

#include <stdio.h>

int main() {
    char name[100];
    char city[100];

    printf("Enter your name: ");
    scanf("%*s");  // 跳过输入的字符串，不存储到name变量
    printf("Enter your city: ");
    scanf("%s", city);  // 将输入存储到city变量

    printf("City: %s\n", city);

    return 0;
}

In this example, %*s is used to skip the user-entered name, and %s is used to read the user-entered city. Therefore, the name entered by the user will be ignored, only the city will be read and printed.

Precautions

The %*s format specifier cannot actually be used directly to skip whitespace. It is used to skip strings regardless of whether there are spaces in the string. When using %*s, it ignores the entire string, including all characters in it, including spaces.