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atoll() Function with Example in C++

C++ atoll() function: Here, we are going to learn about the atoll() function with example of cstdlib header in C++ programming language.
Submitted by IncludeHelp, on May 26, 2020

C++ atoll() function

atoll() function is a library function of cstdlib header. It is used to convert the given string value to the integer value. It accepts a string containing an integer (integral) number and returns its long long long integer value.

Syntax

Syntax of atoll() function:

C++11:

long long int atoll (const char * str);

Parameter(s)

• str – represents a string containing an integer (integral) number.

Return value

The return type of this function is long long int, it returns the long long long integer converted value.

Sample Input and Output

Input:
str = "123456789012345";

Function call:
atoll(str);

Output:
123456789012345

Example

C++ code to demonstrate the example of atoll() function:

// C++ code to demonstrate the example of
// atoll() function

#include <iostream>
#include <cstdlib>
#include <string.h>
using namespace std;

// main() section
int main()
{
    char str[50];

    strcpy(str, "123456789");
    cout << "atoll(\"" << str << "\"): " << atoll(str) << endl;

    strcpy(str, "-123456789");
    cout << "atoll(\"" << str << "\"): " << atoll(str) << endl;

    strcpy(str, "0");
    cout << "atoll(\"" << str << "\"): " << atoll(str) << endl;

    strcpy(str, "9876543120");
    cout << "atoll(\"" << str << "\"): " << atoll(str) << endl;

    strcpy(str, "-9876543120");
    cout << "atoll(\"" << str << "\"): " << atoll(str) << endl;

    strcpy(str, "123456789012345");
    cout << "atoll(\"" << str << "\"): " << atoll(str) << endl;

    return 0;
}

Output

atoll("123456789"): 123456789
atoll("-123456789"): -123456789
atoll("0"): 0
atoll("9876543120"): 9876543120
atoll("-9876543120"): -9876543120
atoll("123456789012345"): 123456789012345

Reference: C++ atoll() function