What are the situations of deep copy of javascript?
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Deep copy: the name in the reference data type exists in the stack memory and the value exists in the heap memory, but the stack memory provides a referenced address to the value in the heap memory. The deep copy is to add a pointer and apply for a new memory, so that the added pointer points to the new memory. Method 1: use Object.assign (), which is generally used for data with simple data type and no more than 1 layer, because Object.assign cannot be copied deeply.
Const strJson = {id:'12343231', name:' Zhang San', age:23, inof: {sex:' male'}, sjid:null, strHandle () {console.log ('111111111');}} obj.name =' lisi' obj.inof.sex = 'female' console.log ('obj',obj); console.log (' strJson',strJson)
Results:
Method 2: use JSON.parse and JSON.stringify, which are generally used for data with complex data types and deeply nested data, but undefined, function, RegExp and other types cannot be processed.
Const strJson = {id:'12343231', name:' Zhang San', age:23, inof: {sex:' Man'}, sjid:null, strHandle () {console.log ('111111111') }} const obj = JSON.parse (JSON.stringify (strJson)) obj.name = 'lisi' obj.inof.sex =' female 'console.log (' obj',obj); console.log ('strJson',strJson)
Results:
Third: use recursive copies to handle special cases in the code.
Function copyHandle (strJson) {let result; / / determine whether there is if (! strJson) return null; / / determine whether it is an object if (typeof strJson! = = 'object') return strJson; / / determine whether it is an array if (Array.isArray (strJson)) {result = [] For (let i of strJson) {result.push (copyHandle (I)}} / / determine whether it is RegExp else if (strJson.constructor===RegExp) {result = strJson} / / determine whether it is an object else {result = {} for (let i in strJson) {result [I] = copyHandle (strJson [I]) }} / / return result return result} above is the content of this article on "what is the situation of deep copy of javascript?" I believe we all have a certain understanding. I hope the content shared by the editor will be helpful to you. If you want to know more about the relevant knowledge, please pay attention to the industry information channel.
