apply
accepts an array and it applies the array as parameters to the actual function. So,
Math.max.apply(Math, list);
can be understood as,
Math.max("12", "23", "100", "34", "56", "9", "233");
So, apply
is a convenient way to pass an array of data as parameters to a function. Remember
console.log(Math.max(list)); # NaN
will not work, because max
doesn’t accept an array as input.
There is another advantage, of using apply
, you can choose your own context. The first parameter, you pass to apply
of any function, will be the this
inside that function. But, max
doesn’t depend on the current context. So, anything would work in-place of Math
.
console.log(Math.max.apply(undefined, list)); # 233
console.log(Math.max.apply(null, list)); # 233
console.log(Math.max.apply(Math, list)); # 233
Since apply
is actually defined in Function.prototype
, any valid JavaScript function object, will have apply
function, by default.