I have this array:
var arr1 = [
{"user":"dan","liked":"yes","age":"22"},
{"user":"sarah","liked":"no","age":"21"},
{"user":"john","liked":"yes","age":"23"},
];
I'd like to create a new (sub)array of that array, containing only the likes of the users.
so it would look like this:
var arr2 = [
{"dan":"yes"},
{"sarah":"no"},
{"john":"yes"},
];
I tried:
var arr2 =[];
for(var i in arr1){
arr2.push({[i[user]]:i[liked]});
}
it needs a tweak, ideas?
Use array.map
var arr1 = [
{"user":"dan","liked":"yes","age":"22"},
{"user":"sarah","liked":"no","age":"21"},
{"user":"john","liked":"yes","age":"23"},
];
var arr2 = arr1.map(v => ({ user: v.user, liked: v.liked }));
console.log(arr2);With your update, although it can be done with array.map, I recommend you use a key-value pair structure instead. You'd need array.reduce.
var arr1 = [
{"user":"dan","liked":"yes","age":"22"},
{"user":"sarah","liked":"no","age":"21"},
{"user":"john","liked":"yes","age":"23"},
];
var arr2 = arr1.reduce((c, v) => (c[v.user] = v.liked, c) , {});
console.log(arr2);Based on your edit:
arr1 = arr1.map(function(item){
return{
[item.user]: item.liked
}
});
var arr1 = [
{"user":"dan","liked":"yes","age":"22"},
{"user":"sarah","liked":"no","age":"21"},
{"user":"john","liked":"yes","age":"23"},
];
var res = arr1.map(function(o) {
var r = {};
r[o.user] = o.liked;
return r;
});
console.log(res);Or in recent ECMAScript versions:
var arr1 = [
{"user":"dan","liked":"yes","age":"22"},
{"user":"sarah","liked":"no","age":"21"},
{"user":"john","liked":"yes","age":"23"},
];
var res = arr1.map(o => ( { [o.user]: o.liked } ));
console.log(res);You could map the deconstructed wanted properties to a new object.
var array1 = [{ user: "dan", liked: "yes", age: "22" }, { user: "sarah", liked: "no", age: "21" }, { user: "john", liked: "yes", age: "23" }],
array2 = array1.map(({ user, liked }) => ({ [user]: liked }));
console.log(array2);ES5
var array1 = [{ user: "dan", liked: "yes", age: "22" }, { user: "sarah", liked: "no", age: "21" }, { user: "john", liked: "yes", age: "23" }],
array2 = array1.map(function (o) {
var temp = {};
temp[o.user] = o.liked;
return temp;
});
console.log(array2);Try this
var arr2 =[];
for(var i in arr1){
var obj= {};
obj[arr1[i]['user']] = arr1[i]['liked'];
arr2.push(obj)
}
var arr2=[];
arr1.forEach(function(obj)
{
var temp=new Object();
temp[obj.user]=obj.liked;
arr2.push(temp);
});
I think this is what you want
array.map will help you, for you understanding since map returns a new array based on your logic, The following example is simple and readable
const arr1 = [
{"user":"dan","liked":"yes","age":"22"},
{"user":"sarah","liked":"no","age":"21"},
{"user":"john","liked":"yes","age":"23"},
];
const arr2 = arr1.map(({user, liked}) => ({ [user]:liked }));
console.log(arr2);if it is an array of objects
var arr1=[{},{},..]
and you have to loop through the objects attributes so you need this
var arr2 =[]
arr1.forEach(element => {
var temp = new Object();
for (var name in element) {
temp[name] = element[name]
}
arr2 .push(temp)
});
now you have arr2 as an other object different from arr1
