phpapprentice/code/comparisons.php

<?php

// A boolean is a value that is always 0 or 1, yes or no, on or off.
// In PHP, a boolean is represented by the words true and false.
// While programming, you will often want to know if something is positive or negative.
$a = true;
$b = false;

// There are many constructs and functions that will return a boolean.
// To start, let's look at comparisons.
$one = 1;
$two = 2;

// Double equals checks if two values are equal.
// This statement will return false.
$one == $two;

// An exclamation point and equal sign check if two values are not equal.
// This statement will return true.
$one != $two;

// You can use greater than and less than symbols to check for comparisons too.
// This statement will return false.
$one > $two;

// This statement will return true.
$one < $two;

// If you combine a greater than or less than symbol with an equal,
// it will check if the value is greater or less than or equal to another value.
$one <= $two;
$one >= $two;

// You can also check that two values are equal and of the same type
// by using three equal signs.

// This returns true.
1 == 1;
1 == '1';
1 == true;
1 == 1.0;
1 === 1;

// This returns false.
1 === '1';
1 === true;
1 === 1.0;