59 lines
1.6 KiB
Markdown
59 lines
1.6 KiB
Markdown
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---
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title: JSON Parse
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---
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## JSON Parse
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The `JSON.parse()` method parses a string and construct a new object described by a string.
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#### Syntax:
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```javascript
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JSON.parse(text [, reviver])
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```
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##### Parameters:
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`text`
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The string to parse as JSON
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`reviver`(Optional)
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The function will receive `key` and `value` as arguments. This function can be used to tranform the result value.
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Here is an example on how to use `JSON.parse()`:
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```javascript
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var data = '{"foo": "bar"}';
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console.log(data.foo); // This will print `undefined` since `data` is of type string and has no property named as `foo`
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// You can use JSON.parse to create a new JSON object from the given string
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var convertedData = JSON.parse(data);
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console.log(convertedData.foo); // This will print `bar
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```
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<a href='https://repl.it/MwgK/0' target='_blank' rel='nofollow'>Repl.it Demo</a>
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Here is an example with `reviver`:
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```javascript
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var data = '{"value": 5}';
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var result = JSON.parse(data, function(key, value) {
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if (typeof value === 'number') {
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return value * 10;
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}
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return value;
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});
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// Original Data
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console.log("Original Data:", data); // This will print Original Data: {"value": 5}
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// Result after parsing
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console.log("Parsed Result: ", result); // This will print Parsed Result: { value: 50 }
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```
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In the above example, all numberic values are being multipled by `10` - <a href='https://repl.it/Mwfp/0' target='_blank' rel='nofollow'>Repl.it Demo</a>
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#### More Information:
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<a href='https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse' target='_blank' rel='nofollow'>JSON.parse - MDN</a>
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