Condition Statement
When writing code, you often need to perform different actions for different judgments.
You can use conditional statements in the code to complete this task.
If... else statement
Execute one piece of code when the conditions are met, and execute another piece of code when the conditions are not met.
Elseif statement
Used with if... else to execute a code block If... Else statement when several conditions are met
If you want to execute some code when a condition is set, and execute other code when the condition is not set, use the if... else statement.
Syntax
If (condition)
Code to be executed if condition is true;
Else
Code to be executed if condition is false;
Instance
If the current date is Friday, the following code will output "Have a nice weekend! ", Otherwise it will output" Have a nice day! ":
Copy codeThe Code is as follows: <Body>
<? Php
$ D = date ("D ");
If ($ d = "Fri ")
Echo "Have a nice weekend! ";
Else
Echo "Have a nice day! ";
?>
</Body>
</Html>
If you need to execute multiple lines of code when the conditions are true or fail, you should include these lines in curly brackets:
Copy codeThe Code is as follows: <Body>
<? Php
$ D = date ("D ");
If ($ d = "Fri ")
{
Echo "Hello! <Br/> ";
Echo "Have a nice weekend! ";
Echo "See you on Monday! ";
}
?>
</Body>
</Html>
ElseIf statement
To execute code when multiple conditions are created, use the elseif statement:
Syntax
Copy codeThe Code is as follows: if (condition)
Code to be executed if condition is true;
Elseif (condition)
Code to be executed if condition is true;
Else
Code to be executed if condition is false;
Instance
If the current date is Friday, the following example will output "Have a nice weekend! ", If it is Sunday, output" Have a nice Sunday! ", Otherwise output" Have a nice day! ":
Copy codeThe Code is as follows: <Body>
<? Php
$ D = date ("D ");
If ($ d = "Fri ")
Echo "Have a nice weekend! ";
Elseif ($ d = "Sun ")
Echo "Have a nice Sunday! ";
Else
Echo "Have a nice day! ";
?>
</Body>
</Html>