C atol() function
C atol() function - Convert a string to a long integer
The atol() function is used to convert a character string to a long value.
Syntax:
long int atol(const char *str)
Parameters:
Name | Description | Required /Optional |
---|---|---|
str | String to be converted. | Required |
Return value from atol()
- Returns a long value.
Example: atol() function
The following example shows the usage of atol() function.
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
int main(void)
{
char *str = NULL;
long value = 0;
// string value with leading and trailing white spaces.
str = " -7435 ";
value = atol( str );
printf( "Function: atol( \"%s\" ) = %d\n", str, value );
// string value with an arbitrary decimal point.
str = "732946.45";
value = atol( str );
printf( "Function: atol( \"%s\" ) = %d\n", str, value );
// Another example with an overflow condition occurring.
str = "234243820342342-422348";
value = atol( str );
printf( "Function: atol( \"%s\" ) = %d\n", str, value );
if (errno == ERANGE)
{
printf("Overflow condition occurred.\n");
}
}
Output:
Function: atol( " -7435 " ) = -7435 Function: atol( "732946.45" ) = 732946 Function: atol( "234243820342342-422348" ) = 598985798
C Programming Code Editor:
Previous C Programming: C atoi()
Next C Programming: C strtod()
C Programming: Tips of the Day
What's the point of const pointers?
const is a tool which you should use in pursuit of a very important C++ concept:
Find bugs at compile-time, rather than run-time, by getting the compiler to enforce what you mean.
Even though it does not change the functionality, adding const generates a compiler error when you're doing things you didn't mean to do. Imagine the following typo:
void foo(int* ptr) { ptr = 0;// oops, I meant *ptr = 0 }
If you use int* const, this would generate a compiler error because you're changing the value to ptr. Adding restrictions via syntax is a good thing in general. Just don't take it too far -- the example you gave is a case where most people don't bother using const.
Ref : https://bit.ly/33Cdn3Q
- Weekly Trends
- Java Basic Programming Exercises
- SQL Subqueries
- Adventureworks Database Exercises
- C# Sharp Basic Exercises
- SQL COUNT() with distinct
- JavaScript String Exercises
- JavaScript HTML Form Validation
- Java Collection Exercises
- SQL COUNT() function
- SQL Inner Join
- JavaScript functions Exercises
- Python Tutorial
- Python Array Exercises
- SQL Cross Join
- C# Sharp Array Exercises