Angularjs: Create an array of keys from json object

Question

I have a json in the following structure:

$scope.hi=[{ "a":1, "b":true, "c":"great" }]; 

I want to extract only the keys and make an array like

$scope.bye=["a","b","c"]; 

Though seems to be a very basic question but would be very helpful for me.

Answer 1

This is what you need

Object.keys($scope.hi[0]); 

This only works in IE9+ if you target IE.

An alternative might be to do fetch them with a loop

var obj = $scope.hi[0], array = []; for (key in obj) { if (obj.hasOwnProperty(key)) { array.push(key); } } 

Also note that the order of the keys may not be respected depending on the browser implementation.

Answer 2

You can use #aduch variant or start to use great lib that called underscorejs

_.keys($scope.hi) // result: ["a","b","c"] 

Answer 3

Just as @aduch said, use

Object.keys($scope.hi[0]). 

Add the following code before making use of it to handle browsers that do not implement Object.keys

// From https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys if (!Object.keys) { Object.keys = (function () { 'use strict'; var hasOwnProperty = Object.prototype.hasOwnProperty, hasDontEnumBug = !({toString: null}).propertyIsEnumerable('toString'), dontEnums = [ 'toString', 'toLocaleString', 'valueOf', 'hasOwnProperty', 'isPrototypeOf', 'propertyIsEnumerable', 'constructor' ], dontEnumsLength = dontEnums.length; return function (obj) { if (typeof obj !== 'object' && (typeof obj !== 'function' || obj === null)) { throw new TypeError('Object.keys called on non-object'); } var result = [], prop, i; for (prop in obj) { if (hasOwnProperty.call(obj, prop)) { result.push(prop); } } if (hasDontEnumBug) { for (i = 0; i < dontEnumsLength; i++) { if (hasOwnProperty.call(obj, dontEnums[i])) { result.push(dontEnums[i]); } } } return result; }; }()); } 

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys