Just wondering why i got an error with the following simple JavaScript function
function highest(){
return arguments.sort(function(a,b){
return b - a;
});
}
highest(1, 1, 2, 3);
Error messsage : TypeError: arguments.sort is not a function.
I am confused as arguments it is an array (i thought). Please help and explain why. Many thanks
Because arguments has no sort method. Be aware that arguments is not an Array object, it's an array-like Arguments object.
However, you can use Array.prototype.slice to convert arguments to an array; and then you will be able to use Array.prototype.sort:
function highest(){
return [].slice.call(arguments).sort(function(a,b){
return b - a;
});
}
highest(1, 1, 2, 3); // [3, 2, 1, 1]
[].sort.call( arguments, function(a,b) { ...
Arguments object, and I prefer using arrays than array-like objects. But true, [].sort.call(arguments) should also work (and according to IETester works even on IE5.5).
use spread syntax to convert arguments to a real Array:
function highest(...arguments){
return arguments.sort(function(a,b){
return b - a;
});
}
highest(1, 1, 2, 3);
Output: (4) [3, 2, 1, 1]
Another way to do this is by declaring the arguments as an array.
var myArguments = [1, 1, 2, 3];
var sortedArguments = [];
Thus the highest() can be defined as;
function highest(myArguments)
{
return myArguments.sort(function(a,b)
{
return b - a;
});
}
sortedArguments = highest(myArguments);
argumentsis not an array, take a look at this demo. It's anArguments Object, which only acts like an array. Same goes to many array-like objects returned by native functions such as.getElementsByClassName, for example, which returns anHTMLCollectionobject.argumentsis not an array. It has a length and indexed properties, but if you checkarguments instanceof Array, you’ll notice that it’sfalse(and thatObject.prototype.toString.call(arguments) === '[object Arguments]'). As such, it doesn’t have methods fromArray.prototype, includingsort.