PHP in a Nutshell

Name

abs()

Synopsis

    number abs ( number num )

The abs() function returns the absolute value of the parameter you pass to it. By absolute, I mean that it leaves positive values untouched, and converts negative values into positive values. Thus:

    abs(50); // 50
    abs(-12); // 12

You can either send a floating-point number or an integer to abs(), and it will return the same type:

    abs(50.1); // 50.1
    abs(-12.5); // 12.5

The abs() function is helpful for handling user input, such as "How many t-shirts would you like to buy?" While you could write code to check for values equal to or under 0, and issue warnings if appropriate, it is easier to put all quantity input through abs() to ensure it is positive.