Question

I already have a function to get substring of a string

void subString(char* buffer, char* str, int start, int length)
{
    int i, x = 0;
    int end=start+length;
    for(i = start ; i <= end; i++)
        buffer[x++] = str[i];
    buffer[x] = '\0';

    //return temp;
}

new string is stored in buffer

but I prefer the function likes

char * subString(char* str, int start, int length)
{

    //.......

}

it will automatically returns the string pointer that has been alloced memory.

Welcome any comment

Answer 1

What’s wrong with just adding the malloc into your new function and leaving the rest the same?

#include<stdlib.h>
char * subString(char* str, int start, int length) {
    char *newString = (char *)malloc(length * sizeof(char));
    int i, x = 0;
    int end=start+length;
    for(i = start ; i <= end; i++)
        newString[x++] = str[i];
    newString[x] = '\0';
    return newString;
}