Question

4. Write a C function int str2int(char *s) that takes string s as parameter and return the integer that s represents. For example, if string s is 123", then the function return integer 123.

Answer 1

#include <string.h>
#include <stdio.h>

#define MAX 100

int str2int(char* s)
{
    int i, len = strlen(s);
    int result = 0;
    for (i = 0; i < len; i++) {
        result *= 10;
        result += (s[i] - '0');
    }
    return result;
}

int main()
{
    char str[MAX];
    printf("Enter string: ");
    scanf("%s", str);
    printf("Output: %d ", str2int(str));
    return 0;
}

Enter string: 12345 Output: 12345 -------------------------------------- Process exited after 2.665 seconds with return value 0 Press any key to continue....