我可以在es6数组解构中使用什么作为占位符？

Question

I don't like the , , here:

let colors = [ "red", "green", "blue" ];
let [ , , thirdColor] = colors;

Can I use some placeholders characters? I'd rather not introduce unused variables, I just want to make the code look clearer. Right now the only thing I can think about are comments:

let [/*first*/, /*second*/, thirdColor] = colors;

Any better ideas?

Answer 1

There is no concept of a placeholder in JS. Often _ is used for this, but you can't actually use it more than once in one declaration:

let [_, secondColor] = colors; // OK
let [_, _, thirdColor] = colors; // error

Also, _ may actually be used in your code, so you'd have to come up with another name, etc.

The simplest way may be to access the third element directly:

let thirdColor = colors[2];
let {2: thirdColor, 10: eleventhColor} = colors;