将javascript关联数组转换为多对象数组

Question

here is my input:

where input may receive more data like 'e:5'

  var input = {a:2,b:3,c:2,d:1};

I want to convert this input into below output:

var output = [{name="a",id="2"},
              {name="b",id="3"},
              {name="c",id="2"},
              {name="d",id="1"}];

thanks in advance.

Answer 1

Use Array#map over Object.keys

The Object.keys() method returns an array of a given object's own enumerable properties.

---

The map() method creates a new array with the results of calling a provided function on every element in this array.

---

 var input = { a: 2, b: 3, c: 2, d: 1 }; var mapped = Object.keys(input).map(function(key) { return { name: key, id: input[key] }; }); console.log(mapped); 

Answer 2

Use can Array#forEach over Object.keys

 var input = {a:2,b:3,c:2,d:1}; var output = []; Object.keys(input).forEach(function(key){ output.push({name:key,id:input[key]}); }) console.log(output); 

Answer 3

Javascript object properties are unordered. Because of that, the order of keys returned from Object.keys is undetermined. In order to maintain the alphabetical order like your example, you need to previously sort the keys , then use map to create a new array with the expected value.

I don't like ES5. So here is my ES6 answer.

Object.keys(input).sort((a, b) => a.localeCompare(b)).map(name => ({name, id: input[name]}));

Answer 4

Just for some fun and for training purposes we may come up with this. Remember that while it's possible to add later, you can always embed a Symbol.iterator method by the constructor function at the time of instantiation and your objects become iterable by default.

 var input = {a:2,b:3,c:2,d:1}, output = []; input[Symbol.iterator] = function*(){ var ok = Object.keys(this), i = 0; while (i < ok.length) yield {[ok[i]]: this[ok[i++]]}; }; for (var keyValuePair of input) output.push(keyValuePair); console.log(output); // or you can even do like output.length = 0; output = [...input]; // cool console.log(output); 

Answer 5

You can also try below approach :

var input = {a:2,b:3,c:2,d:1};

var output = Object.keys(input).reduce(function(p, c){
     return p.concat({name:c, id:input[c]});
}, []);