54 lines
1.1 KiB
Markdown
54 lines
1.1 KiB
Markdown
# defined
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return the first argument that is `!== undefined`
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[](http://ci.testling.com/substack/defined)
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[](http://travis-ci.org/substack/defined)
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Most of the time when I chain together `||`s, I actually just want the first
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item that is not `undefined`, not the first non-falsy item.
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This module is like the defined-or (`//`) operator in perl 5.10+.
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# example
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``` js
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var defined = require('defined');
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var opts = { y : false, w : 4 };
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var x = defined(opts.x, opts.y, opts.w, 100);
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console.log(x);
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```
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```
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$ node example/defined.js
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false
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```
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The return value is `false` because `false` is the first item that is
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`!== undefined`.
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# methods
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``` js
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var defined = require('defined')
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```
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## var x = defined(a, b, c...)
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Return the first item in the argument list `a, b, c...` that is `!== undefined`.
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If all the items are `=== undefined`, return undefined.
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# install
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With [npm](https://npmjs.org) do:
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```
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npm install defined
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```
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# license
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MIT
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