i want to remove the first array element, without modified the original (immutable),
something like this:
function getArray(): number[] {
return [1, 2, 3, 4, 5];
}
function getAnother(): number[] {
const [first, ...rest] = getArray();
return rest;
}
the code works, but the typescript check complained:
'first' is assigned a value but never used @typescript-eslint/no-unused-vars
Is there the elegant/better way to do somilar to getAnother()?
You can ignore an element with a comma.
const [, ...rest] = getArray();
Array#slice can also be used in this case.
const rest = getArray().slice(1);
You can use default Array method
Array.prototype.slice
Try this
function getAnother(): number[] {
return getArray().slice(1)
}
One common practice here is to prefix unused variables or arguments with an underscore, as in one of the following:
const [_first, ...rest] = getArray();
const [_, ...rest] = getArray();
This allows you to still use a visible or labeled placeholder. Though this works without configuration in Visual Studio Code's syntax highlighting, you may need to configure it for your ESLint usage with varsIgnorePattern and argsIgnorePattern, which in ESLint is suggested in documentation as "^_".
arr.slice(1)?