std:🧵:resize() in C++ (original) (raw)

Last Updated : 05 Sep, 2022

resize() lets you change the number of characters. Here we will describe two syntaxes supported by std:🧵:resize() in C++ Return Value : None

Syntax 1: Resize the number of characters of *this to num.

void string ::resize (size_type num) num: New string length, expressed in number of characters. Errors: Throws length_error if num is equal to string ::npos. Throws length_error if the resulting size exceeds the maximum number of characters(max_size()).

Note : If num > size() then, the rest of characters are initialized by the '\0'.

CPP `

// CPP code for resize (size_type num)

#include <iostream> #include <string> using namespace std;

// Function to demonstrate insert void resizeDemo(string str) {

// Resizes str to a string with
// 5 initial characters only 
str.resize(5);
cout << "Using resize : ";
cout << str;

}

// Driver code int main() { string str("GeeksforGeeks ");

cout << "Original String : " << str << endl;
resizeDemo(str);

return 0;

}

`

Output:

Original String : GeeksforGeeks Using resize : Geeks

Syntax 2: Uses a character to fill the difference between size() and num.

void string ::resize (size_type num, char c ) num: is the new string length, expressed in number of characters. c: is the character needed to fill the new character space. If num > size() : character c is used to fill space. If num < size() : String is simply resized to num number of characters. Errors: Throws length_error if num is equal to string ::npos. Throws length_error if the resulting size exceeds the maximum number of characters(max_size()).

CPP `

// CPP code for resize (size_type num, char c )

#include <iostream> #include <string> using namespace std;

// Function to demonstrate insert void resizeDemo(string str) { cout << "Using resize :" << endl; cout << "If num > size() : ";

// Resizes str to character length of
// 15 and fill the space with '$'
str.resize(15, '$');
cout << str << endl;
cout << "If num < size() : ";

// Resizes str to a string with
// 5 initial characters only 
str.resize(5, '$');
cout << str;

}

// Driver code int main() { string str("GeeksforGeeks");

cout << "Original String : " << str << endl;
resizeDemo(str);

return 0;

}

`

Output:

Original String : GeeksforGeeks Using resize : If num > size() : GeeksforGeeks$$ If num < size() : Geeks

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