This article introduces the usage of switch statements in php. It is similar to switch usage in other statements, but note that there is a break statement.
Standard syntax for switch statements in PHP:
switch (expression)
{
case label1:
code to be executed if expression = label1;
break;
case label2:
code to be executed if expression = label2;
break;
default:
code to be executed
if expression is different from both label1 and label2;
}
For example:
switch($i){
case 1:
echo 1;
break;
case 2:
echo 2;
break;
default:
echo 'others';
}
You can also use switch to determine a value range, or customize the conditions in the case.
<?php
header("content-type:text/html;charset=utf8");
$score=50;
switch($score)
{
case $score>=90 && $score<=100:
echo "Excellent<br>";
break;
case $score>=80 && $score<90:
echo "Good<br>";
break;
case $score>=70 && $score<80:
echo "In the meantime<br>";
break;
case $score>=60 && $score<70:
echo "Pass<br>";
break;
case $score>=0 && $score<60:
echo "Failed<br>";
break;
default:
echo"Score entry error<br>";
}
?>
Simple example
<?php
//Switch details //Scenario 1: When the numerical value matches, it will automatically convert into strings. $a=1;
switch($a){
case "1":
echo 'hello1';
break;
default:
echo 'sorry none is the same!';
break;
}
echo '<br/>'.'Exit successfully...';
echo '<hr/>';
//Scenario 2: Automatically convert into characters when the numerical values match $a=1;
switch($a){
case '1':
echo 'hello2';
break;
default:
echo 'sorry none is the same!';
break;
}
echo '<br/>'.'Exit successfully...';
echo '<hr/>';
//Scenario 3: Automatically convert to numeric values when characters match $a='1';
switch($a){
case 1:
echo 'hello3';
break;
default:
echo 'sorry none is the same!';
break;
}
echo '<br/>'.'Exit successfully...';
echo '<hr/>';
//Scenario 4: Automatically convert to numerical values when string matches $a="1";
switch($a){
case 1:
echo 'hello4';
break;
default:
echo 'sorry none is the same!';
break;
}
echo '<br/>'.'Exit successfully...';
echo '<hr/>';
//Scenario 5: float can also match $a=1.1;
switch($a){
case 1.1:
echo 'hello5';
break;
default:
echo 'sorry none is the same!';
break;
}
echo '<br/>'.'Exit successfully...';
echo '<hr/>';
//Scenario 6: Non-0 is true $a=true;
switch($a){
case 1:
echo 'hello6';
break;
case true:
echo 'hello61';
break;
default:
echo 'sorry none is the same!';
break;
}
echo '<br/>'.'Exit successfully...';
echo '<hr/>';
//Scenario 7: Can match boolean $a=true;
switch($a){
case true:
echo 'hello7';
break;
case 2:
echo 'hello71';
break;
default:
echo 'sorry none is the same!';
break;
}
echo '<br/>'.'Exit successfully...';
echo '<hr/>';
//Scenario 8: Can match null $a=null;
switch($a){
case 2://'' "" false 0 can enter echo 'hello8';
break;
case null:
echo 'hello81';
break;
default:
echo 'sorry none is the same!';
break;
}
echo '<br/>'.'Exit successfully...';
echo '<hr/>';
//Scenario 9: Exit order $a=5;
switch($a){
case 1:
echo 'hello6';
break;
case 2:
echo 'I'm Exit 2';
break;
case 5:
echo 'I'm Exit 5';
//break;
case true:
echo 'hello61';
break;
default:
echo 'sorry none is the same!';
break;
}
echo '<br/>'.'Exit successfully...';
echo '<hr/>';
//Scenario 10: Exit order $a=50;
switch($a){
default:
echo 'sorry none is the same!';
//break;
case 50:
echo 'hello6';
//break;
case 2:
echo 'I'm Exit 2';
break;
case 5:
echo 'I'm Exit 5';
//break;
case 6:
echo 'hello61';
break;
}
echo '<br/>'.'Exit successfully...';
echo '<hr/>';
?>
Running results
hello1 Exit successfully···· hello2 Exit successfully···· hello3 Exit successfully···· hello4 Exit successfully···· hello5 Exit successfully···· hello6 Exit successfully···· hello7 Exit successfully···· hello81 Exit successfully···· I am5Exit numberhello61 Exit successfully···· hello6I am2Exit number Exit successfully····