About PHP If ... Else statement operation using the

Conditional statements are used to perform different actions based on different conditions, and this article details the relevant knowledge points of the conditional statement.

PHP conditional statements

When you write code, you often need to perform different actions for different judgments. You can use conditional statements in your code to accomplish this task.

In PHP, the following conditional statements are available:

If statement-executes code when conditions are true

If...else statement-Executes a piece of code when the condition is set, and executes another piece of code when the condition is not true

If...elseif....else Statement-executes a block of code when one of several conditions is established

Switch statement-executes a block of code when one of several conditions is established

Php-if statements

The IF statement is used to execute code only when the specified condition is true.

Grammar

if (condition) {The code to execute when the condition is established;}

If the current time is less than 20, the following instance will output "a good day!" ：

Instance

<?php$t=date ("H"), if ($t < ") {    echo" has a good day! ";}? >

Running Instances»

Php-if...else statements

Execute a piece of code when the condition is established, and execute another piece of code when the condition is not established, using the If....else statement.

Grammar

if (condition)
{
Code executed when the condition is established;
}
Else
{
Code executed when the condition is not established;
}

If the current time is less than 20, the following instance outputs "a good day!", otherwise the output "has a good night!" ：

Instance

<?php$t=date ("H"), if ($t < ") {    echo" has a good day! ";} else{    echo "Have a good night!";}? >

Running Instances»

Php-if...elseif....else statements

To execute a block of code when one of several conditions is true, use the If....elseif...else statement:

Grammar

if (condition)
{
The code executed when the condition is established;
}
ElseIf (condition)
{
ElseIf code executed when the condition is established;
}
Else
{
Code executed when the condition is not established;
}

If the current time is less than 10, the following instance will output "a good morning!", if the current time is not less than 10 and less than 20, the output "has a good day!", otherwise the output "has a good night!" ：

Instance

<?php$t=date ("H"), if ($t < "ten") {    echo "has a good morning!";} ElseIf ($t < ") {    echo" has a good day! ";} else{    echo "Have a good night!";}? >

This article explains in detail the relevant knowledge points of the conditional statements, and more study materials are concerned about the PHP Chinese network.