PHPGurukul

Functions In PHP

  • A block of code for specific tasks.
  • Save compile time –only compile once.
  • Reuse many times when needed.
  • Optimize your code.
  • Built-in functions like print(); date();

    • User-defined functions:
    • Function names cannot have spaces.
    • Function name must begin with letter or underscore.

    E.g., call a built-in function abs();

    <?php
    $num=-5;
    $new_num=abs($num);
    echo $new_num;
    ?>

    Declaring a Function

    function function_name(arguments)
    {
    block of codes and statements;
    }
    • You can declare a function below a call to it.
    • May have none, one, or multiple arguments each separated by a comma.
    • Write function name followed by ( ), even if the function doesn’t have any arguments.

    Example-

    <?php
    function print_br($str) {
    print "$str <br>";
    }
    print_br("line1");
    print_br("line2");
    ?>

    Functions – Return Value

    • Functions may have a return value.
    • A return value in a function, returns the value to the function that may be used later on while calling a function.
    • You may need to access the value that the function returns, but you may not need to print it out, that’s why you use a return value for a function.

    Example-Functions – Return Value

    <?php
    function multiply_by_two($value){
    $result=$value*2;
    return $result;
    }
    echo multiply_by_two(7);
    ?>

    Example-Functions – Without Return Value

    <?php
    function multiply_by_two($value){
    $result=$value*2;
    echo $result;
    }
    multiply_by_two(7);
    ?>

    PHP built-in Functions
    Sqrt(); — Take the square root of a number
    Ceil(); — Take ceil of a decimal number
    Floor(); — take the floor of a decimal number
    Max(); — take the max number
    Min(); — take the min number
    Strtolower(); — convert string to lower case
    Strtoupper(); — convert string to upper case

Anuj Kumar

This is Anuj Kumar. I’m a professional web developer with 4+ year experience. I write blogs in my free time. I love to learn new technologies and share with others.
I founded PHPGurukul in September 2015. The main aim of this website to provide PHP, Jquery, MySQL, PHP Oops and other web development tutorials.
.

Recommended Tutorials for you


Add comment

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Follow us

Don't be shy, get in touch. We love meeting interesting people and making new friends.