错误表达式必须有指向 object 类型的指针

Question

#include <stdio.h>
int length(char s)
{ int i;
    for(i=0;s[i]!='\0';i++)
    {}
    printf("%d",i);
}

int main()
{
    char s[100];
    scanf("%s",s);
    length(s);
    

}

I am trying to write a simple program which prints the no. of characters in a string wihtout using strlen but i am getting these error messages which are beyond my scope of understanding as of now.

Answer 1

Since you are initiated your function as Integer , you should return any argument in the function length . But also you print something of length function then you should use function as void

#include<stdio.h>

void length(char *s)
{
    int i;
    for(i=0;s[i]!='\0';i++){}
    printf("%d",i);
}

int main()
{
    char s[100];
    scanf("%s",s);
    length(s);
    return 0;

}

Furthermore, You pass just a character array and you run a loop for the character that's why it showing an exception. If you want you to alive your function as integer then pass a character array like,

#include<stdio.h>

int length(char *s)
{
    int i;
    for(i=0;s[i]!='\0';i++){}
    printf("%d",i);
}

int main()
{
    char s[100];
    scanf("%s",s);
    length(s);
    return 0;

}

Answer 2

#include <stdio.h>
int length(char s[])
{ int i;
    for(i=0;s[i]!='\0';i++)
    {}
    printf("%d",i);
}

int main()
{
    char s[100];
    scanf("%s",s);
    length(s);
    

}`

Found my mistake