Question

Implement two functions in C language:

stringLength() - Takes a pointer to a string, and a pointer to an int variable. It computes the length of the string and updates the int variable with the length.

stringCopy() - Copies one string onto another using pointers

#include<stdio.h>

#define MAX_STR_LEN 2048

void stringLength(char *str, int *len)

{

// This function computes the length of the string

// at the address in the pointer *str. Once the length

// has been determined, it updates the length

// variable OUTSIDE this function whose address is

// given by the pointer *len

//

// Note - the length can not be more than MAX_STR_LEN

// TO DO:

// Complete this function!

// YOU ARE NOT ALLOWED TO USE FUNCTIONS FROM THE STRING LIBRARY

}

void stringCopy(char *destStr, char *srcStr)

{

// This function copies the contents of a string whose address

// is given by the pointer *srcStr to the string whose address

// is given by the pointer *destStr.

// Note that the function should never try to copy more than

// MAX_STR_LEN characters

// TO DO:

// Complete this function!

// YOU ARE NOT ALLOWED TO USE FUNCTIONS IN THE STRING LIBRARY

}

int main()

{

char string1[MAX_STR_LEN]="To see a world in a grain of sand,";

char string2[MAX_STR_LEN]="And a heaven in a wild flower.";

int len1,len2;

len1=0;

len2=0;

printf("%s\n",string1);

printf("%s\n",string2);

// DO NOT CHANGE ANYTHING ABOVE THIS LINE for main()

// In the space below, complete the code for each step

// 1 - Update len1 and len2 with the length of the

// corresponding strings (complete the stringLength()

// function for this!)

// DO NOT CHANGE THE PRINT STATEMENTS BELOW

printf("String 1 is %d characters long\n",len1);

printf("String 2 is %d characters long\n",len2);

// 2 - Copy string1 to string2 (after you do this, string2

// should contain 'To see a world in a grain of sand,'

// complete the function stringCopy() for this part

// DO NOT CHANGE ANYTHING BELOW THIS LINE

printf("%s\n",string1);

printf("%s\n",string2);

return 0;

}

Answer 1

#include<stdio.h>

#define MAX_STR_LEN 2048

void stringLength(char *str, int *len) {
// This function computes the length of the string
// at the address in the pointer *str. Once the length
// has been determined, it updates the length
// variable OUTSIDE this function whose address is
// given by the pointer *len
//
// Note - the length can not be more than MAX_STR_LEN
// TO DO:
// Complete this function!
// YOU ARE NOT ALLOWED TO USE FUNCTIONS FROM THE STRING LIBRARY
    int count = 0;
    while (str[count]) {
        count++;
    }
    *len = count;
}

void stringCopy(char *destStr, char *srcStr) {
// This function copies the contents of a string whose address
// is given by the pointer *srcStr to the string whose address
// is given by the pointer *destStr.
// Note that the function should never try to copy more than
// MAX_STR_LEN characters
// TO DO:
// Complete this function!
// YOU ARE NOT ALLOWED TO USE FUNCTIONS IN THE STRING LIBRARY
    int i = 0;
    while (srcStr[i]) {
        destStr[i] = srcStr[i];
        i++;
    }
}

int main() {
    char string1[MAX_STR_LEN] = "To see a world in a grain of sand,";
    char string2[MAX_STR_LEN] = "And a heaven in a wild flower.";
    int len1, len2;
    len1 = 0;
    len2 = 0;
    printf("%s\n", string1);
    printf("%s\n", string2);
// DO NOT CHANGE ANYTHING ABOVE THIS LINE for main()
// In the space below, complete the code for each step
// 1 - Update len1 and len2 with the length of the
// corresponding strings (complete the stringLength()
// function for this!)
    stringLength(string1, &len1);
    stringLength(string2, &len2);
// DO NOT CHANGE THE PRINT STATEMENTS BELOW
    printf("String 1 is %d characters long\n", len1);
    printf("String 2 is %d characters long\n", len2);
// 2 - Copy string1 to string2 (after you do this, string2
// should contain 'To see a world in a grain of sand,'
// complete the function stringCopy() for this part
    stringCopy(string2, string1);
// DO NOT CHANGE ANYTHING BELOW THIS LINE
    printf("%s\n", string1);
    printf("%s\n", string2);
    return 0;
}