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Replace all occurrences of a string with space
• Difficulty Level : Basic
• Last Updated : 26 Sep, 2019

Given a string and a substring, the task is to replace all occurrences of the substring with space. We also need to remove trailing and leading spaces created due to this.

Examples:

Input: str = “LIELIEILIEAMLIECOOL”, sub = “LIE”
Output: I AM COOL
By replacing all occurrences of Sub in Str with empty spaces, we extract the secret message as I AM COOL.

Input: str = “XYZAXYZBXYZC”, sub = “XYZ”
Output: ABC
By replacing all occurrences of Sub in Str with empty spaces, we extract the secret message as ABC.

## Recommended: Please solve it on “PRACTICE” first, before moving on to the solution.

Approach:

• In the given string Str, replace all occurrences of Sub with empty spaces.
• Remove unwanted empty spaces in start and end of the string.
• Print the modified string.

Below is the implementation of the above approach:

## C++

 `// C++ implementation to extract ``// the secret message``#include ``using` `namespace` `std;`` ` `// Trim method implementation to remove ``// trailing and leading white-spaces``string trim(``const` `string &s)``{``    ``auto` `start = s.begin();``    ``while` `(start != s.end() && ``           ``isspace``(*start))``        ``start++;`` ` `    ``auto` `end = s.end();``    ``do``    ``{``        ``end--;``    ``} ``while` `(distance(start, end) > 0 && ``                    ``isspace``(*end));`` ` `    ``return` `string(start, end + 1);``}`` ` `// Function to extract the secret message``string extractSecretMessage(string str, ``                            ``string sub)``{``    ``// Replacing all occurrences of``    ``// Sub in Str by empty spaces``    ``size_t` `pos;``    ``while` `((pos = str.find(sub)) != string::npos)``        ``str.replace(pos, 3, ``" "``);`` ` `    ``// Removing unwanted spaces in the``    ``// start and end of the string``    ``str = trim(str);`` ` `    ``return` `str;``}`` ` `// Driver code``int` `main(``int` `argc, ``char` `const` `*argv[])``{``    ``string str = ``"LIELIEILIEAMLIECOOL"``;``    ``string sub = ``"LIE"``;``    ``cout << extractSecretMessage(str, sub) ``         ``<< endl;``    ``return` `0;``}`` ` `// This code is contributed by``// sanjeev2552`

## Java

 `// Java implementation to extract the secret message``import` `java.io.*;``import` `java.util.*;`` ` `class` `GFG {`` ` `    ``// Function to extract the secret message``    ``static` `String extractSecretMessage(String Str, String Sub)``    ``{``        ``// Replacing all occurrences of``        ``// Sub in Str by empty spaces``        ``Str = Str.replaceAll(Sub, ``" "``);`` ` `        ``// Removing unwanted spaces in the``        ``// start and end of the string``        ``Str = Str.trim();`` ` `        ``return` `Str;``    ``}`` ` `    ``// Driver code``    ``public` `static` `void` `main(String args[])``    ``{``        ``String Str = ``"LIELIEILIEAMLIECOOL"``;``        ``String Sub = ``"LIE"``;``        ``System.out.println(extractSecretMessage(Str, Sub));``    ``}``}`

## Python3

 `# Python3 implementation to extract``# the secret message`` ` `# Function to extract the secret message``def` `extractSecretMessage(``Str``, Sub):`` ` `    ``# Replacing all occurrences of``    ``# Sub in Str by empty spaces``    ``Str``=` `Str``.replace(Sub, ``" "``)`` ` `    ``# Removing unwanted spaces in the``    ``# start and end of the string``     ` `    ``return` `Str``.strip()`` ` `# Driver code``Str` `=` `"LIELIEILIEAMLIECOOL"``Sub ``=` `"LIE"``print``(extractSecretMessage(``Str``, Sub))`` ` `# This code is contributed ``# by ihritik`

## C#

 `// C# implementation to extract the ``// secret message ``using` `System;`` ` `class` `GFG ``{ `` ` `// Function to extract the secret message ``static` `string` `extractSecretMessage(``string` `Str, ``                                   ``string` `Sub) ``{ ``    ``// Replacing all occurrences of ``    ``// Sub in Str by empty spaces ``    ``Str = Str.Replace(Sub, ``" "``); `` ` `    ``// Removing unwanted spaces in the ``    ``// start and end of the string ``    ``Str = Str.Trim(); `` ` `    ``return` `Str; ``} `` ` `// Driver code ``public` `static` `void` `Main() ``{ ``    ``string` `Str = ``"LIELIEILIEAMLIECOOL"``; ``    ``string` `Sub = ``"LIE"``; ``    ``Console.WriteLine(extractSecretMessage(Str, Sub)); ``} ``} `` ` `// This code is contributed by Ryuga`

## PHP

 ``
Output:
```I AM COOL
```

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