I am doing a standard task with codewares: Write function bmi that calculates body mass index (bmi = weight / height2).
Here is my solution:
function bmi(weight, height) {
let bmi = weight / (height ** 2)
if (bmi <= 18.5) {
return "Underweight";
} else if (bmi <= 25.0) {
return "Normal"
} else if (bmi <= 30.0) {
return "Overweight"
} else if (bmi > 30) {
return "Obese"
}
}
console.log(bmi(80, 1.80))I have a question: is it possible to solve this problem with the help of a switch? Because I tried it in different ways and in the console I have undefined:
function bmi(weight, height) {
let bmi = weight / (height ** 2)
let c = "Normal"
switch (bmi) {
case "Underweight":
bmi <= 18.5;
break;
case "Normal":
bmi <= 25.0;
break;
case "Overweight":
bmi <= 30.0;
break;
default:
return;
}
}
console.log(bmi(80, 1.80))(Thanks to user derpirscher for pointing out I had provided a completely incorrect answer. I've updated a corrected answer below.)
Unfortunately this syntax for switch statements, where your case is a complex comparison against the expression, is not supported in JS. Cases are simply checked against the expression for a simple match. While one could do something like this:
function bmi(weight, height) {
let bmi = weight / (height ** 2)
let c = "Normal"
switch (true) {
case bmi <= 18.5:
c = "Underweight";
break;
case bmi <= 25.0:
c = "Normal";
break;
case bmi <= 30.0:
c = "Overweight";
break;
default:
c = "Obese"
}
return c;
}
console.log(bmi(8, 1.80))
console.log(bmi(80, 1.80))
console.log(bmi(800, 1.80))It is using the switch for a case different than its intended purpose.
This is not necessarily a readable or expressive way of writing this-- I think your original approach with the if...else is probably preferable to a switch-based approach.