switchThe conventional usage is to pass a parameter and compare it with the case one by one;
switch (variable) {
case 'value':
// code...
break;
default:
// code...
break;
}When there are many branches; switch is better than if else if is easy to use; for example;
if('value'){
// code...
}else if('value2'){
// code...
}else if('value3'){
// code...
}else if('value4' || 'value5'){
// code...
} If you write it with switch, you can pass true; each case is equivalent to an else if;
switch ('value') {
case 'value1':
// code...
break;
case 'value2':
// code...
break;
case 'value3':
// code...
break;
case 'value4':
case 'value5':
// code...
break;
}However, it should be noted that switch is a loose comparison; that is to say, the following code can satisfy every case;
switch (123) {
case 'string':
// code...
break;
case 'string2':
// code...
break;
case 'string3':
// code...
break;
}The way to solve this problem is to convert it to string when passing parametersstring type;
switch (strval(123)) {
case 'string':
// code...
break;
case 'string2':
// code...
break;
case 'string3':
// code...
break;
}The above is the detailed content of Detailed explanation of switch usage extension in php. For more information, please follow other related articles on the PHP Chinese website!
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