Given a JavaScript object, how can I convert it into an array of objects (each with key, value)?
Example:
var data = { firstName: 'John', lastName: 'Doe', email: '[email protected]' }
resulting like:
[
{ key: 'firstName', value: 'John' },
{ key: 'lastName', value: 'Doe' },
{ key: 'email', value: '[email protected]' }
]
var data = { firstName: 'John', lastName: 'Doe', email: '[email protected]' }
var output = Object.entries(data).map(([key, value]) => ({key,value}));
console.log(output);Inspired By this post
Using map function
var data = { firstName: 'John', lastName: 'Doe', email: '[email protected]' };
var result = Object.keys(data).map(key => ({ key, value: data[key] }));
console.log(result);
arrow function
key => ({ key, value: data[key] }) You can just iterate over the object's properties and create a new object for each of them.
var data = { firstName: 'John', lastName: 'Doe', email: '[email protected]' };
var result = [];
for(var key in data)
{
if(data.hasOwnProperty(key))
{
result.push({
key: key,
value: data[key]
});
}
}
hasOwnProperty
hasOwnProperty but down for not doing it in a functional way, like @isvforallES6 way does not mean this is a not reliable (even great and far more readable) answer. A downvote seems odd.Object.keys and Array.map is all good old EcmaScript 5.1. (Yes the arrow function @isvforall used is ES6 but not really an interesting part of the answer, e.g see the answer by @rob-brander)
The previous answer lead me to think there is a better way...
Object.keys(data).map(function(key) {
return { key, value: data[key] };
});
or in ES6 using arrow functions:
Object.keys(data).map((key) => ({ key, value: data[key] }));
Unexpected token :
Just make your life easier and use es6 syntax with a map
var output = Object.keys(data).map(key => {
return {
key: key,
value: data[key]
};
})
var result = [];
for(var k in data) result.push({key:k,value:data[k]});
Or go wild and make the key and value keys customizable:
module.exports = function objectToKeyValueArray(obj, keyName = 'key', valueName = 'value') {
return Object
.keys(obj)
.filter(key => Object.hasOwnProperty.call(obj, key))
.map(key => {
const keyValue = {};
keyValue[keyName] = key;
keyValue[valueName] = obj[key];
return keyValue;
});
};
An alternative method for doing this that works on multi level objects and does not use recursion.
var output = []
var o = {
x:0,
y:1,
z:{
x0:{
x1:4,
y1:5,
z1:6
},
y0:2,
z0:[0,1,2],
}
}
var defer = [ [ o ,[ '_root_' ] ] ]
var _defer = []
while(defer.length){
var current = defer.pop()
var root = current[1]
current = current[0]
for(var key in current ){
var path = root.slice()
path.push(key)
switch( current[key].toString() ){
case '[object Object]':
_defer.push( [ current[key] , path ] )
break;;
default:
output.push({
path : path ,
value : current[key]
})
break;;
}
}
if(!defer.length)
defer = _defer.splice(0,_defer.length)
}
[
{ path: [ '_root_', 'x' ], value: 0 },
{ path: [ '_root_', 'y' ], value: 1 },
{ path: [ '_root_', 'z', 'y0' ], value: 2 },
{ path: [ '_root_', 'z', 'z0' ], value: [ 0, 1, 2 ] },
{ path: [ '_root_', 'z', 'x0', 'x1' ], value: 4 },
{ path: [ '_root_', 'z', 'x0', 'y1' ], value: 5 },
{ path: [ '_root_', 'z', 'x0', 'z1' ], value: 6 }
]
const array = [
{ key: "key1", value: "value1" },
{ key: "key2", value: "value2" },
];
const obj = Object.fromEntries(array.map(item => [item.key, item.value]));
console.log(obj);
I would say to use npm package flat. works amazing for nested objects and arrays.
var flatten = require('flat')
flatten({
key1: {
keyA: 'valueI'
},
key2: {
keyB: 'valueII'
},
key3: { a: { b: { c: 2 } } }
})
// {
// 'key1.keyA': 'valueI',
// 'key2.keyB': 'valueII',
// 'key3.a.b.c': 2
// }
const array = [
{ key: "key1", value: "value1" },
{ key: "key2", value: "value2" },
];
const obj = Object.fromEntries(array.map(item => [item.key, item.value]));
console.log(obj);
