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joshaber/file.js

Last active April 19, 2016 17:41
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file.js
let thing: ?string = ... // `thing` is a nullable string
if (thing) {
// Within this `if`, `thing` is of type `string`. No longer nullable.
}
// Outside the `if`, `thing` is still a nullable string.
if (!thing) return
// Since we returned if `thing` is null, `thing` is now of type `string`.
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