Please explain c_str() and

#1

while(key > 1){
key–; //why we did this?
}

1 Like
#2

@Devansh_29 The basic_string::c_str() is a builtin function in C++ which returns a pointer to an array that contains a null-terminated sequence of characters representing the current value of the basic_string object. This array includes the same sequence of characters that make up the value of the basic_string object plus an additional terminating null-character at the end.

Syntax:

const CharT* c_str() const
Parameter: The function does not accept any parameter

Return Value : The function returns a constant Null terminated pointer to the character array storage of the string.

Below is the implementation of the above function:

Program 1
// C++ code for illustration of
// basic_string::c_str function
#include <bits/stdc++.h>
#include
using namespace std;

int main()
{
// declare a example string
string s1 = “GeeksForGeeks”;

// check if the size of the string is same as the 
// size of character pointer given by c_str 
if (s1.size() == strlen(s1.c_str())) { 
    cout << "s1.size is equal to strlen(s1.c_str()) " << endl; 
} 
else { 
    cout << "s1.size is not equal to strlen(s1.c_str())" << endl; 
} 

// print the string 
printf("%s \n", s1.c_str());

}
Output:
s1.size is equal to strlen(s1.c_str())
GeeksForGeeks

1 Like
#3

@Devansh_29 hey isme , while(key > 1){
key–; //why we did this?
}
Key jab tk 1 se bdi hai tab tk ye loop chlega aur andr loop ke k-- krrhe hai taki k jo hai 1 tk pahunch jaye aur loop khtm hojaye.

1 Like
#4

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