string erase in C++

Last Updated : 23 Apr, 2025

The string erase() function is a built-in function of the string class that is used to erase the whole or part of the string, shortening its length. The function provides different ways to delete a portion of a string based on either an index position or a range of characters or delete the whole string.

Example :

C++

//Driver Code Starts{ #include <iostream> #include <string> using namespace std;  int main() { //Driver Code Ends }      string str = "Hello, World!";      // Erase a single character sterting     // from index 5     str.erase(5, 1);  //Driver Code Starts{          cout << str;     return 0; } //Driver Code Ends }

Output

Hello World!

Syntax

The string erase() function provides 5 different overloads for different purposes:

C++

s.erase()                   // Erases whole string s.erase(idx)             // Erases all characters after idx s.erase(idx, k)        // Erases k characters after idx s.erase(itr)             // Erases character at itr s.erase(first, last) // Erases character in range [first, last)

Let’s look at how to use each overload one by one.

Table of Content

Erase Single Character from Given Position

string erase() function can be used for erasing a single character from the specific position in the string.

Syntax

C++

s.erase(itr)

Parameters

itr: Iterator to the character you want to erase (note that it is an iterator, not index)

Return Value

Returns the character now at the position of the removed character.
If no such character is remaining, returns iterator to the string::end()

Example

C++

#include <iostream> #include <string> using namespace std;  int main() {     string s("Hello World!");      // Deletes character at position 4     s.erase(s.begin() + 4);      cout << s;     return 0; }

Output

Hell World!

Erase Range of Characters

We can also erase a range of characters from the string using string erase() function.

Syntax

C++

s.erase(first, last)

Parameters

first: Iterator to the first element in the range.
last: Iterator to one element after the last element in the range.

Return Value

Returns the character now at the position of the first removed character.
If no such character is remaining, returns iterator to the string::end()

Example

C++

#include <bits/stdc++.h> using namespace std;  int main() {     string s("Hello World!");      // Define the range as the word "Hello "   	auto first = s.begin();   	auto last = s.begin() + 6;   	   	// Remove the range [first, last)     s.erase(first, last);        cout << s;     return 0; }

Output

World!

Erase k Characters After Given Position

The below version erases all the characters after the given index, but we can also limit the number of characters to be deleted using string::erase.

Syntax

C++

s.erase(idx, k)

Parameters

idx: The position (index) at which character deletion begins.
k: Number of characters to be erased (including character at idx).

Return Value

This version returns the current string.

Example

C++

#include <bits/stdc++.h> using namespace std;  int main() {     string s("Hello World!");      // Deletes 5 characters starting from index number 0     s.erase(0, 5);      cout << s;     return 0; }

Output

 World!

Erase All Characters After Given Position

string erase() function can also be instructed to erase the characters after some given position.

Syntax

C++

s.erase(idx)

Parameters

idx: The position (index) at which character deletion begins.

Return Value

This version returns the current string.

Example

C++

#include <bits/stdc++.h> using namespace std;  int main() {     string s("Hello World!");    	// Deletes the word " World!"     s.erase(5);        cout << s;     return 0; }

Output

Hello

Erase All Characters

The string erase() function is able to delete all the characters of the string effectively clearing it. The length of the string will be reduced to 0.

Syntax

C++

s.erase()

Parameter

This version takes no parameters.

Return Value

This version returns the current string.

Example

C++

#include <bits/stdc++.h> using namespace std;  int main() {     string s("Hello World!");      // Erasing string using string::erase()     s.erase();      cout << s;     return 0; }

Output

(no output)

string erase() vs string clear()

The string clear() is a function used to erase the contents of the string, but it is a lot different from string erase(). Below is the table that lists the major differences between string erase() and string clear().

Aspect	`string::erase()`	`string::clear()`
Purpose	Removes specific characters or a range of characters.	Removes all characters from the string.
Syntax	erase(position); erase(first, last);	clear();
Parameters	– Position of a single character – Range of characters (two iterators)	None
Returns	Iterator pointing to the position after the removed range	None
Time Complexity	– Single character: O(m), where m is the number of characters after the position. – Range: O(m – k), where k is the size of the range.	O(1), where n is the number of characters in the string.
Space Complexity	O(1), as it modifies the string in place.	O(1), as it clears the string in place.

String find() in C++

Sakshi Tiwari

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string erase in C++

Syntax

Erase Single Character from Given Position

Syntax

Example

Erase Range of Characters

Syntax

Example

Erase k Characters After Given Position

Syntax

Example

Erase All Characters After Given Position

Syntax

Example

Erase All Characters

Syntax

Example

string erase() vs string clear()

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