Usage examples of JavaScript switch case [scope]_javascript skills

A few examples:

Copy code The code is as follows:

function case1 (num){
switch(num){
case 1:
document.writeln("show 1!!");
break;
case 2:
document.writeln ("show 2!!");
break;
case 3:
document.writeln("show 3!!");
break;
default:
document. writeln("show others!!");
break;
}
}
function case2(num){
switch(num){
case 1:
document .writeln("show 1!!");
//There is no break, so case 2 will continue to be executed
case 2:
document.writeln("show 2!!");
break ;
case 3:
document.writeln("show 3!!");
//There is no break, so case 4 will continue to be executed
case 4:
document.writeln(" show 4!!");
break;
default:
document.writeln("show others!!");
break;
}
}
function case3 (num){
switch(num){
case 1:
case 2:
//Equivalent to if(num==1 || num==2)
document.writeln ("show 1 or 2!!");
break;
case 3:
case 4:
//Equivalent to if(num==3 || num==4)
document.writeln("show 3 or 4!!");
break;
default:
//Equivalent to else
document.writeln("show others!!");
break;
}
}
function case4(num){
switch(f(num)){
case 1:
case 2:
//Equivalent if(num==1 || num==2)
document.writeln("show 1 or 2!!");
break;
case 3:
case 4:
//equivalent to if(num==3 || num==4)
document.writeln("show 3 or 4!!");
break;
default:
//equivalent in else
document.writeln("show others!!");
break;
}
}
function f(num){
return num;
}
function case5(num){
switch(num<=2){
case true:
document.writeln("num <= 2");
break;
case false:
document.writeln("num > 2");
break;
}
}

JavaScript switch case statement setting range

[Ctrl A select all Note: If you need to introduce external Js, you need to refresh to execute

]<script> var x=10 switch(true){ case x>0&&x<10: alert(1); break; case x>=10&&x<20: alert(2); break; } </script>