What are the unusual uses of JSON stringify ()

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JSON.stringify () serializes only traverable properties (enumerable=true)

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Varobj= {}

Object.defineProperties (obj, {

'foo': {

Value:1

Enumerable:true

}

'bar': {

Value:2

Enumerable:false

}

})

JSON.stringify (obj); / / "{" foo ": 1}"

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JSON.stringify (obj,fn | arr)

1) when the second parameter is an array, it represents the list of attributes of the object that needs to be serialized

2) when the second parameter is a method, function (key,value) {} represents the key-value value corresponding to each attribute, and the final return value can be used to change the original result.

This method can be used to change the contents of an object before serialization.

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Varo= {a: {b:1}}

Functionf (key,value) {

Console.log ("[" + key+ "]:" + value)

Returnvalue

}

JSON.stringify (ofline f)

/ / []: [objectObject]

/ / [a]: [objectObject]

/ / [b]: 1

/ /'{"a": {"b": 1}}'

/ / Recursive processing, the last returned result is processed each time

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JSON.stringify (obj,null,number | string)

You can accept the third parameter, which can be used to print objects in format

When the third parameter is a numeric value, it represents the number of spaces before each attribute