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35 lines
756 B
Markdown
35 lines
756 B
Markdown
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---
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id: 8659a753-2c0d-46cb-afdc-095e318aabff
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title: Closure in JavaScript
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---
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Local bindings are created anew for every call, and different calls
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can't affect on another calls local bindings.
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``` javascript
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function wrapValue(n) {
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let local = n;
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return () => local;
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}
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let wrap1 = wrapValue(1);
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let wrap2 = wrapValue(2);
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console.log(wrap1());
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console.log(wrap2());
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```
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A function that references bindings from local scopes around it is
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called a closure. This behavior not only frees you from having to worry
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about lifetimes of bindings but also makes it possible to use function
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values in some creative ways.
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``` javascript
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function multiplier(factor) {
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return number => number * factor;
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}
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let twice = multiplier(2);
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console.log(twice(5));
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```
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