how to design switch condition in JavaScript Thanks

Question

if the cases are range, may I use "0<a<5" as a case condition?
::>_<:: I tried and it only check if a<5.
so the minus checking should be in another case or a range can be a casa condition but I make some syntax errors〒_〒l

var a=-6

switch (true){
case 0<a<5:
alert(1)
break;
Case a>=5:
Alert(2)
Break;.....}

~(*+﹏+*)~

Answer 1

suppose a are integers between 0, 1, 2, 3... 8, 9

to separate 1 - 4 from others

the code snippet should be

switch (a) {

case 0:
console.log('a is 0');
break;

case 1:
case 2:
case 3:
case 4:
console.log('0<a<5');
break;

case 5:
case 6:
case 7:
case 8:
console.log('4<a<9');
break;

case 9:
console.log('a is 9');
break;

default:
console.log('Invalid value of a');

}

https://code.sololearn.com/WLUw7woWzCB8/?ref=app

1. break; is used to separate conditions.

2. Put the variables in the parentheses after switch

See?

Answer 2

yes switch is for discrete cases, for example, integers.

If the variable will lie within a range, you need to use if-else statements, sometimes nested if necessary

if (kpi<0){
console.log("error");
}else{
if(kpi<90){
console.log("small");
}else{
if(kpi<200){
console.log("large");
}else{
console.log("abnormal");
}
}
}

suppose you have two valid range, you need to handle the out-of-boundary values as well.

Answer 3

https://love2dev.com/blog/javascript-switch-statement/

according to the KPI example in this page, the case can be KPI>=90 bigger or equal, but my case 0<a<5 is not accepted. There is also the method mentioned by Gordon, thanks and it is perfect for limit number of cases.

my BMI code
https://code.sololearn.com/WTSL2hwKrpqP/?ref=app