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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 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.

Example:

    Input:
    str = "123456789012345";

    Function call:
    atoll(str);

    Output:
    123456789012345

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