Hi.. i need help with a code that replace word entered in a string. Pls tell the mistake or share some other code?

Question

#include <stdio.h>
#include<string.h>
int main(void) {int len;
 char str[100],d[100][100],a[100],b[100];
printf("enter the string\n");
scanf("%[^\n]s",str);
len=strlen(str);
int i=0;int j=0;int k;
for(;i<len;i++)
{if(str[i]==' ')k=0;
  if(str[i]!=' ')
{d[j][k]=str[i];k++;
if(str[i+1]==' ')
j++;}}
printf("enter the word to be replaced\n");
scanf("%s",a);
printf("enter the replaced word\n");
scanf("%s",b);
int l=0;
for(;l<=j;l++)
if(strcmp(a,d[l])==0)
strcpy(d[l],b);
printf("the new string is as folows\n");
int w=0;
for(;w<=j;w++)
printf("%s ",d[w]);
  return 0; }

Answer 1

Please add comments in the code you share ,it will help make things clearer to others.

Always indent your code ,its easy to look at blocks of structured code & make sense of the code.

Always provide initial values to variables ,C language may have garbage initial values to  uninitialised variables.

I could not  understand why below code was written,but has few issues

---

int i=0;int j=0;int k;    //K can have junk values & could give 
                         //funny results when used as index in array :)
for(;i<len;i++)
{if(str[i]==' ')k=0;    //if source string has spaces , k=0 
                        //but what if no spaces are ever found ??
  if(str[i]!=' ')      
{d[j][k]=str[i];k++;   //possible case of garbage value of K read & incremented
if(str[i+1]==' ')      
j++;}}

---

Assuming the word is always a single character & we have to replace all the occurences of that character with a user input character ,below is what i did.

---

#include <stdio.h>
#include <string.h>
int main(void) {
        int len;
        char str[100],d[100][100]; //,a[100],b[100];
        char a=' ';
        char b=' ';
        printf("enter the string\n");
        scanf("%[^\n]s",str);
        len=strlen(str);
        int i=0;int j=0;int k;
        /*  
        for(;i<len;i++)
        {
                if(str[i]==' ') k=0;
                if(str[i]!=' ')
                {
                    d[j][k]=str[i];k++;
                    if(str[i+1]==' ')
                                j++;
                }
        }
        */
        printf("enter the word to be replaced\n");
        scanf(" %c",&a);
        printf("enter the replaced word\n");
        scanf(" %c",&b);
        int l=0;
        /*for(;l<=j;l++)
                if(strcmp(a,d[l])==0)
                        strcpy(d[l],b);
        */
        for(i=0;i<len;i++)
        {   
            if(str[i]==a)
            {   
                str[i]=b;   
            }
        }   
        printf("the new string is as folows\n");
        printf("%s ",str);
        return 0;
}
/*
output
enter the string
sttttringgg
enter the word to be replaced
t
enter the replaced word
x
the new string is as folows
sxxxxringgg 
*/