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* Javascript -> JavaScript (English) * Update technical documentation page for required change * Update use-class-syntax-to-define-a-constructor-function.english.md * Update left-factorials.md
43 lines
1.7 KiB
Markdown
43 lines
1.7 KiB
Markdown
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title: Global Object
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---
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The global object is an object that is initialized by the JavaScript interpreter before the code is executed. All variables that are declared on the global scope (see: <a href='http://forum.freecodecamp.com/t/scopes-in-javascript/14696' target='_blank' rel='nofollow'>Scopes</a>) are stored in the global object as properties.
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In a Node.js environment, the global object can be accessed by the `global` keyword, while in a browser window it can be accessed by the `window` keyword. The `this` keyword also refers to the global object when used in the global scope. Please note that using `this` in the global scope will return `undefined` if `strict mode` is enabled.
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For example:
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```javascript
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// global scope
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var foo = "bar";
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console.log(global.foo); // bar (in a Node environment)
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console.log(window.foo); // bar (in a browser window)
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console.log(this.foo); // bar (if strict mode is disabled)
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```
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The distinction between scopes local to functions and the global scope is important here: the global object only contains the variables that were declared on the global scope, not the local scopes of functions.
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The global object also contains the properties `NaN`, `undefined` and `Infinity` and the following functions:
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1. `decodeURI()`
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2. `decodeURIComponent()`
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3. `encodeURI()`
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4. `encodeURIComponent()`
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5. `escape()`
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6. `eval()`
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7. `GetObject()`
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8. `isFinite()`
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9. `isNaN()`
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10. `parseFloat()`
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11. `parseInt()`
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12. `ScriptEngine()`
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13. `ScriptEngineBuildVersion()`
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14. `ScriptEngineMajorVersion()`
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15. `ScriptEngineMinorVersion()`
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16. `unescape()`
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# References
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1. MSDN: <a href='https://msdn.microsoft.com/en-us/library/52f50e9t' target='_blank' rel='nofollow'>Global Object (JavaScript)</a>
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