What's the Difference Between Pre- and Post-Increment/Decrement Operators in PHP?

Reference Guide: What does this symbol mean in PHP? (PHP Syntax)

In PHP, the and -- operators are used for incrementing or decrementing variables.

Increment Operator ( )

• Pre-increment ( $variable): Increments the variable by one and then returns the incremented value.
• Post-increment (variable ): Returns the current value of the variable, then increments it by one.

Decrement Operator (--)

• Pre-decrement (--variable): Decrements the variable by one and then returns the decremented value.
• Post-decrement (variable--): Returns the current value of the variable, then decrements it by one.

Usage

These operators can be used before or after the variable to achieve different results:

• Pre-increment/decrement: The variable is modified before it is used.
• Post-increment/decrement: The variable is used and then modified.

Example

Consider the following code:

$count = 10;
echo "Before: $count\n";
echo "Pre-increment: " . ++$count . "\n";
echo "Post-increment: " . $count++ . "\n";
echo "Pre-decrement: " . --$count . "\n";
echo "Post-decrement: " . $count-- . "\n";

Output

Before: 10
Pre-increment: 11
Post-increment: 11
Pre-decrement: 10
Post-decrement: 10

This demonstrates how the increment/decrement operators can be used in different scenarios. Notice that in the post-increment and post-decrement cases, the original value of the variable is used first before being modified.

The above is the detailed content of What's the Difference Between Pre- and Post-Increment/Decrement Operators in PHP?. For more information, please follow other related articles on the PHP Chinese website!