Can I declare type for variable one using JSDoc @type annotation?

/** @type some.type */
for (let one of many) {
    ...
}

Something like PHPDoc annotation:

/** @var \Some\Type $one */
foreach ($many as $one) {

}

Can I declare type for variable one using JSDoc @type annotation?

/** @type some.type */
for (let one of many) {
    ...
}

Something like PHPDoc annotation:

/** @var \Some\Type $one */
foreach ($many as $one) {

}

• javascript
• types
• ecmascript-6
• annotations
• jsdoc

• I don't think I'd normally expect type declarations inside a function. Wouldn't you look at the documentation for whatever created many? – loganfsmyth Commented Jul 13, 2017 at 5:31
• 1 @loganfsmyth , I use PHPDoc @var annotations in any place of my code to annotate the type of any variable. Can I do the same with JSDoc? – Alex Gusev Commented Jul 13, 2017 at 7:46

1 Answer 1

Yes, you can. You just have to move the type declaration inside of the parentheses, before your variable:

for (/** @type {SomeType} */ const one of many) {
    // ...
}

This works just fine, although I usually prefer specifying the type of many instead. For instance:

/** @type {Number[]} */
const many = [1, 2, 3, 4];

And then the type of one will be automatically inferred.

P.S.: notice I declared one as const. Despite of what one may guess, you can declare for..of loop variables as constants!