php expression, php regular expression_PHP tutorial

php expression, php regular expression

Expression is an important concept in PHP. An expression can be understood as "anything with value". In this tutorial, when it comes to the syntax of expressions, we use "expr" to represent expressions.

The following is an expression:

$x > $y;

In the above example, when the value of $x is greater than $y, the expression value is TRUE, otherwise it is FALSE.

We often determine our next step logic by judging the value of an expression (including specific numerical values ​​and Boolean values), such as the following example:

<?php
if ($x > $y) {
     echo "x > y";
}
?>

This example uses if logical judgment. The judgment condition is the $x > $y expression in parentheses. If $x > $y is true (TRUE), then the words "y > x" will be output. Of course, the actual situation is much more complicated.

Expressions are widely used in our PHP programming.

Original address: http://www.manongjc.com/php/php_expressions.html

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