C++ <string> - resize() Function

The C++ string::resize function is used to resize the string to a length of specified number of characters (n). If n is less than the current string length then the content is reduced to the first n characters of the string. If n is greater than the current string length, then the new characters are inserted at the end of the string. If c is specified, then new characters are initialized with c, else they are value-initialized.

Syntax

• C++98
• C++11

void resize (size_t n);
void resize (size_t n, char c);

void resize (size_t n);
void resize (size_t n, char c);

Parameters

Return Value

None.

Time Complexity

Linear i.e, Θ(n).

Example:

In the example below, the string::resize function is used to resize the string str.

#include <iostream>
#include <string>

using namespace std;
 
int main (){
  string str = "Learn Python";

  //size of the string is reduced to 6
  str.resize(6);

  //size of the string is expanded to 7 with character 'C'
  str.resize(7, 'C');
  //size of the string is expanded to 9 with character '+'
  str.resize(9, '+');

  cout<<"str contains: "<<str;
  return 0;
}

The output of the above code will be:

str contains: Learn C++