find and replace words in C++ - c++

Question

I have a program to find and replace words in C++.
#include<iostream.h>
#include<string.h>
int main()
{
char string[80], replace[80], found[80], str1[80], str2[80], str3[80];
cout << "\nEnter string(max 3 words)\n";
cin.getline(string , 80);
cout << "\nEnter the word to be Found\n";
cin.getline(found , 80);
cout << "\nReplace with \n";
cin.getline(replace , 80);
for(int i = 0; string[i] != '\0'; i++)
{
str1[i] = string[i];
if(str1[i] == " ")
break;
}
for(int j = i; string[j] != '\0'; j++)
{
str2[j] = string[j];
if(str2[j] == " ")
break;
}
for(int k = j; string[k] != '\0'; k++)
{
str3[k] = string[k];
if(str3[k] == " ")
break;
}
cout << str1;
cout << str2;
cout << str3;
}
For this I stored every word as a different string, but it doesn't help.
What should be done to improve this?

Answer 1

Your code has too many logical & syntactical error.
Here is the modified code which will accept the required string and print expected output:
#include<iostream>
#include<string.h>
using namespace std;
void strreplace(string orgString, const string search, const string replace )
{
for( size_t pos = 0; ; pos += replace.length() )
{
pos = orgString.find( search, pos );
if( pos == string::npos )
break;
orgString.erase( pos, search.length() );
orgString.insert( pos, replace);
cout<<"String after replacement:"<<orgString<<endl;
}
}
int main()
{
char string[80], replace[80], found[80], str1[80], str2[80], str3[80] ;
cout << "\nEnter string(max 3 words)\n" ;
cin.getline(string , 80);
cout <<"\nEnter the word to be Found\n";
cin.getline(found , 80);
cout <<"\nReplace with \n" ;
cin.getline(replace , 80);
strreplace(string, found, replace);
return 0;
}
I hope this will help you.

Answer 2

In your current code you need to:
Use single quotes to compare characters for equality, not double quotes
Increment another index in your second and third loops. This is because the index for str2 and str3 needs to start at 0, not at the current position being looked at in string
Initalize the main string index (i) in second and third loops with (current value + 1) to skip past the space that it is currently at.
Null terminate your str1, str2, str3
1
if(str1[i] == " ")
should be
if(str1[i] == ' ')
2,3 Instead of
for(int j = i;string[j] != '\0' ; j++)
do
for (int j = 0, i = (i + 1); string[i] != '\0'; j++,i++)
The assignment becomes
str2[j] = string[i];
Do the same for the 3rd loop (without the int in front of j or use another letter). For consistency you could add a j variable starting at 0 to the first loop as well.
4 After each loop add an assignment statement for the null terminator (every c-string needs '\0' at the end to work properly) :
str1[i] = '\0';
str2[j] = '\0';
str3[j] = '\0';

Answer 3

std::string doesn't contain such function instead you could use stand-alone replace function from algorithm header.
#include <algorithm>
#include <string>
string stringReplace(std::string toSearch, std::string toReplace, std::string originalString) {
std::replace( originalString.begin(), originalString.end(), 'toSearch', 'toReplace'); // replace all 'toSearch' to 'toReplace'
return originalString;
}