How to modify an array and convert it to JSON

问题:

I have an array:

[ 'Item 1', 'Item 2', 'Item 3' ]

I need the final result to be

{ 'Item 1':true, 'Item 2':true, 'Item 3':true }

Using ES6 I got kinda close with this:

        let arr = [];
        for (let m of crmData.modRequired) {
            let i = m + ':true';
            arr.push(i);
        }
        modReq = JSON.stringify(arr);
        modReq = modReq.replace(/\[/, '{');
        modReq = modReq.replace(/\]/, '}');

But that produced: {"Quotes:true","Flight Logs:true","Currency Records:true","FTD:true","Maintenance Tracker:true"}

回答1:

You can do this very easily with Object.assign and Array.map, like so:

The idea is to map your array of values into an array of objects that follow the {"ItemX": true} pattern, and then combine them into a single object using Object.assign.

var items = ["Item 1", "Item 2", "Item 3"];

var mapped = Object.assign({}, ...items.map(item => ({[item]: true})));

console.log(JSON.stringify(mapped));

回答2:

You should be able to do this using the array .reduce method. That will turn the array into the object you want. Then you can use JSON.stringify to transform that into a json string.

const myArray = [ 'Item 1', 'Item 2', 'Item 3' ]

// I need the final result to be
// { 'Item 1':true, 'Item 2':true, 'Item 3':true }

const myObj = myArray.reduce((obj, key) => {
  obj[key] = true;
  return obj;
}, {});

console.log("javascript object:", myObj);
console.log("json string:", JSON.stringify(myObj))

回答3:

Just build the object as you loop the array (one step) and you won't have to replace any braces or brackets.

var ary = [ 'Item 1', 'Item 2', 'Item 3' ];
var obj = {};
ary.forEach(function(itm) { obj[itm] = true; } );
console.log(obj);
objJSON = JSON.stringify(obj);
console.log(objJSON);

回答4:

Use the function reduce with Spread Syntax

var array = [ 'Item 1', 'Item 2', 'Item 3' ],
    result = array.reduce((a, c) => ({...a, ...{[c]: true}}), {});

console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

Using forEach

var array  = [ 'Item 1', 'Item 2', 'Item 3' ],
    result = {};

array.forEach(c => result[c] = true);
console.log(result);

.as-console-wrapper { max-height: 100% !important; top: 0; }

回答5:

use .forEach

let arr = [ 'Item 1', 'Item 2', 'Item 3' ];
let newArr = {};
arr.forEach(item=>{
  newArr[item] = true;
});
console.log(newArr);

however i prefer mhodges answer:

let arr = [ 'Item 1', 'Item 2', 'Item 3' ];
console.log(Object.assign({}, ...arr.map(item => ({[item]: true}))))