map integer 到 Javascript 中其他变量的正确方法是什么

Question

I would like to link integer => something in JavaScript without need of iterating over each element of array. In PHP for example I can use arbitrary values without making array bigger.

Let's say my test JS code would be

let experiment = [];
experiment[1] = "hello";
experiment[1000] = "world";
console.log(experiment);

Given this example code, that array contains many empty elements, which implies it's not correct way to do this. I could in theory do array of objects where {int:1,val:'hello'} but this would require me to iterate over said array to access one of elements, which is not what I need.

Is there better way to do this in JavaScript? If not, how bad is that method, like what's the amount of wasted memory for this?

Answer 1

Change experiment = [] to experiment = {} .

Answer 2

You want use an object instead of array. You need not iterate over all keys to find the value. For example experiment[1000] will find the value "world" in constant time O(1) complexity.

 let experiment = {}; experiment[1] = "hello"; experiment[1000] = "world"; console.log(experiment); console.log(experiment[1]); console.log(experiment[1000]);