CODEWITHSUNDEEP
javascriptvisual-studio-codesubstr
user18318036
user18318036

Reputation: 69

Why does the JavaScript substr function have a strikethrough effect in VS Code?

let thesentence = 'I having a good day'
console.log(thesentence.substr(0,4))

the substr has a strikethrough effect, but using substring is fine.

Upvotes: 3

Views: 1594

Answers (1)

starball
starball

Reputation: 52080

It's crossed out because it's deprecated. That's a JS/TS VS Code feature that deprecated things are displayed with a strikethrough effect.

If you mouseover it and wait for the hover info to appear, you'll see this:

@deprecated — A legacy feature for browser compatibility

The @deprecated annotation in the doc comment of the typings (defined by lib.es5.d.ts (part of TypeScript)) is what makes VS Code know that it's deprecated. You can find the change that marked it as deprecated in the TypeScript typings in this commit: Update lib types to mark Annex B as deprecated (#43710)

To read about why substr is deprecated, see Why is String.prototype.substr() deprecated?.

Upvotes: 1

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