javascript-objects

问题 I have an array of arrays of objects which looks like this: let fruitSamples = [ [ {'id': 1,'type': 'apples','samples': [1, 2, 3]}, {'id': 2,'type': 'bananas','samples': [1, 2, 7]}, {'id': 3,'type': 'pears','samples': [1, 2, 3]} ], [ {'id': 1,'type': 'apples','samples': [5, 2, 9]}, {'id': 2,'type': 'bananas','samples': [1, 7, 7]}, {'id': 3,'type': 'pears','samples': [12, 21, 32]} ], [ {'id': 1,'type': 'apples','samples': [11, 2, 33]}, {'id': 2,'type': 'bananas','samples': [17, 2, 67]}, {'id':

问题 I’m trying to convert each integer in a string to its corresponding value in an object based on its key–value entries. For example if I have: var arr = { "3": "value_three", "6": "value_six", "234": "other_value" }; var str = "I want value 3 here and value 234 here"; I would expext the output to be: new_str = "I want value_three here and value other_value here" 回答1: I'm just doing this off the top of my head, but this should work. var new_str = str; for (var key in arr) { if (!arr

问题 This question already has answers here : How do I add a delay in a JavaScript loop? (31 answers) Closed 8 months ago . I am new to javascript so sorry if I am misunderstanding how the language does some stuff, I am building a sorting algorithms visualizer which orders blocks by their hue value (using chroma-js library) : Each item in screenObject.items is a Color object //color objects are what I am sorting class Color { constructor(div, color, value) { //this div on the html page this.div =

问题 I have the below data pushing from a Query we are passing. I have successfully passed the Query into a CSV but we need data to be extracted from Columns rather than Query. Below is a pseudo code how I would want to extract data. The data which is coming out of the Query in a Console is [ The output I am receiving in the Excel sheet is The red Highlighted header in the excel sheet is the field in the Query, But I need the Name of from the column. Below is the code i have written to achieve

问题 Let us suppose we have an object profile with properties name and getName method (arrow function). profile = { name: 'abcd', getName: () => { console.log(this.name); } } I want to call getName method by keeping the arrow function intact, and not changing it to regular function. How can I get the output abcd by calling getName() . You can add expressions inside getName . Will call() or bind() help? If so, how? DO NOT CHANGE THE ARROW FUNCTION TO REGULAR FUNCTION -- EDITED -- I just want to ask

问题 How to filter array by comparing two arrays of objects with different elements in their objects? I have: arr1 =[{ x: 1, y: 2, z:3 }, { x: 2, y: 1, z:4 }]; arr2 = [{ x: 1, y: 2, a:5 }, { x: 2, y: 3, a:4 }]; I want to compare x and y values from both arrays and return the not macthing object from first array, in the above example return [{ x: 2, y: 1, z:4 }] I tried to use _.differenceWith(arr1, arr2, _.isEqual); but obviously for this the arrays should have similar objects which is not my case

问题 I'm getting stuck on a stubborn bug in my MEPN app. This pseudo-code is supposed to assemble a Mongoose query from the options submitted in a user form, and then search a collection using that query. var query = []; query.push("{name:"+req.body.name+"}"); query.push("{status:{$in:["+req.body.statusarray+"]}}"); query.push("{range:{$gte:"+req.body.min+",$lte:"+req.body.max+"}}"); Collection.find(query, function(error, cursor){ if(error) console.log("ERROR: "+error); else //do something })

问题 I am new to JSON and getting this exception while using reviver parameter in JSON.parse(): TypeError: Cannot read property 'name' of undefined(…). Without reviver parameter code works fine but with reviver parameter it throws the above exception. Why is that happening ? var str = ' { ' + ' "name" : "Username", ' + ' "fname" : "Fathername" ' + ' } '; var jObj = JSON.parse(str, function (a, b) { console.log(a + "=>" + b); }); document.write( "<h1>" + jObj.name + "</h1>", "<h2>" + jObj.fname + "

问题 I am new to JSON and getting this exception while using reviver parameter in JSON.parse(): TypeError: Cannot read property 'name' of undefined(…). Without reviver parameter code works fine but with reviver parameter it throws the above exception. Why is that happening ? var str = ' { ' + ' "name" : "Username", ' + ' "fname" : "Fathername" ' + ' } '; var jObj = JSON.parse(str, function (a, b) { console.log(a + "=>" + b); }); document.write( "<h1>" + jObj.name + "</h1>", "<h2>" + jObj.fname + "

问题 I know that this question may have been asked before but I believe that this awesome community can forgive me for this :) I am developing (Quiz time) app but there's a bug that's is killing me :( When I run this application every and press the lock button it acts as wanted but after a random number of clicks (may be 4 or 2) It stops and gives me this error : Uncaught TypeError: Cannot read property 'quest' of undefined at QuestionReset Here's the code $(document).ready(function () { var