文字列の長さを調べる

明解Ｃ言語 入門編 > 9. 文字列の基本 >

文字列の長さを調べる

C

#include <stdio.h>

#include <string.h>
unsigned str_length(const char str[])

{

    unsigned len = 0;
    while (str[len])

        len++;
    return len;

}
int main(int argc, char* argv[])

{

    char str[100] = "ABC";
    printf("sizeof(\"%s\") = %u\n", str, (unsigned)sizeof(str));

    printf("strlen(\"%s\") = %u\n", str, strlen(str));

    printf("str_length(\"%s\") = %u\n", str, str_length(str));
    return 0;

}

実行結果

T:\>lesson072\Project1.exe

sizeof("ABC") = 100

strlen("ABC") = 3

str_length("ABC") = 3