I am studying javascript and here is my problem.
They gave me the variable named "couldBeAnything" which can be any data type. And another variable which named result, too. I must check if the given variable is array then assign true to result. Other cases then false to result. Here is the code.
function checkIsArray(couldBeAnything) {
var result = true ? Array.isArray(couldBeAnything) == true : false
return result;
}
Sorry for my wonder, because this code is from my senior, so I can not understand it clearly, I just only understand if else, so could you please explain this code for me ? How dose it work ? Thank you very much.
This is working because it's doing several pointless operations that complicate reading it, but it's really just using Array.isArray.
Array.isArray(couldBeAnything) == true
If an array is passed in, Array.isArray is true, true == true is true.
So what you get is, if an array is passed in:
var result = true ? true : false;
Which is true.
And for a non-array:
var result = true ? false : false;
Which is false.
This is hopefully the result of several refactorings or lazy merges, because writing this on purpose is pretty silly as others have stated.
I think you are have not been exposed to ternary operators.
let x=true
let result
if(x){
result="Thats true"
}
else{
result="No thats false"
}
console.log(result)
The above can be written as
let x=true
let result=x?"That's true":"No that's false"
console.log(result)
The logic is that if the expression before ? is true then the code after the ? will be executed and if it's false then the code after : will be executed.
That's simple, right?
In your case the code is wrong. It should be like this:
function checkIsArray(couldBeAnything) {
var result = Array.isArray(couldBeAnything) ? true : false
return result;
}
But there is no need for ternary conditions here. You can directly use this
function checkIsArray(couldBeAnything) {
return Array.isArray(couldBeAnything)
}