This is one of those questions I'm ashamed to even ask, but I'm working with an external JSON source and I'm forced to do something ugly. So here goes...
I have 'dirty' Javascript object, with property names containing a number at their end:
{ "Friend1" : "Bob",
"Friend6" : "Fred",
"Friend632" : "Gonzo",
"FriendFinder1" : "Dolly",
"FriendFinder4294" : "Jan"
}
I'm trying to figure out a way to clean-up/"zero-index" these property names so the object would look like:
{ "Friend0" : "Bob",
"Friend1" : "Fred",
"Friend2" : "Gonzo",
"FriendFinder0" : "Dolly",
"FriendFinder1" : "Jan"
}
I'm referencing this indexOf/Regex code:
Is there a version of JavaScript's String.indexOf() that allows for regular expressions?
Any strategies you could recommend for doing this? I'll post where I'm at in a bit. Many thanks!
Take the "base" of a key and append items with a common base to an array using the original index. (This produces a sparse array.) Then stretch it out again by enumerating each item with a common base into a new key with 'base'+enumeratedindex.
The trick here is to use a method like forEach to enumerate the array--this will only visit assigned items in a sparse array, allowing you to determine the sort order just by using the original index-part of the key.
If you don't have access to forEach, you can accomplish a similar task by including the key in the array items. Instead of an intermediate array like this:
{Friend: [undefined, "Bob", undefined, undefined, undefined, undefined, "Fred"]}
You have one like this:
{Friend: [[6, 'Fred'],[1, 'Bob']]}
Then you sort the array and visit each item in a foreach loop, extracting the second item.
Here is code:
function rekey(obj) {
var rekey = /^(.*?)(\d+)$/;
var nestedobj = {}, newobj = {};
var key, basekeyrv, newkey, oldidx, newidx;
function basekey(key) {
return rekey.exec(key).splice(1);
}
for (key in obj) {
if (obj.hasOwnProperty(key)) {
basekeyrv = basekey(key);
newkey = basekeyrv[0];
oldidx = parseInt(basekeyrv[1], 10);
if (!nestedobj[newkey]) {
nestedobj[newkey] = [];
}
nestedobj[newkey][oldidx] = obj[key];
}
}
for (key in nestedobj) {
if (nestedobj.hasOwnProperty(key)) {
newidx = 0;
nestedobj[key].forEach(function(item){
newobj[key+newidx++] = item;
});
}
}
return newobj;
}
rekey({
"Friend1" : "Bob",
"Friend6" : "Fred",
"Friend632" : "Gonzo",
"FriendFinder1" : "Dolly",
"FriendFinder4294" : "Jan"
});
produces
{Friend0: "Bob",
Friend1: "Fred",
Friend2: "Gonzo",
FriendFinder0: "Dolly",
FriendFinder1: "Jan"}
Alternatively, without using forEach:
function rekey(obj) {
var rekey = /^(.*?)(\d+)$/;
var nestedobj = {}, newobj = {};
var key, basekeyrv, newkey, oldidx, newidx;
function basekey(key) {
return rekey.exec(key).splice(1);
}
for (key in obj) {
if (obj.hasOwnProperty(key)) {
basekeyrv = basekey(key);
newkey = basekeyrv[0];
oldidx = parseInt(basekeyrv[1], 10);
if (!nestedobj[newkey]) {
nestedobj[newkey] = [];
}
nestedobj[newkey].push([oldidx, obj[key]]);
}
}
for (key in nestedobj) {
if (nestedobj.hasOwnProperty(key)) {
nestedobj[key].sort();
for (newidx = 0; newidx < nestedobj[key].length; newidx++) {
newobj[key+newidx] = nestedobj[key][newidx][1];
}
}
}
return newobj;
}
Could you try doing the following:
{
friend: new Array(),
friendFinder: new Array()
}
then you can:
friend.push() - Add to array
var index = friend.indexOf("Bob") - find in array
friend.splice(index, 1) - remove from the array at index the 1 is for the number to remove.
Related
I've been looking for a while and want a way to sort a Javascript object like this:
{
method: 'artist.getInfo',
artist: 'Green Day',
format: 'json',
api_key: 'fa3af76b9396d0091c9c41ebe3c63716'
}
and sort is alphabetically by name to get:
{
api_key: 'fa3af76b9396d0091c9c41ebe3c63716',
artist: 'Green Day',
format: 'json',
method: 'artist.getInfo'
}
I can't find any code that will do this. Can anyone give me some help?
UPDATE from the comments:
This answer is outdated. In ES6 objects keys are now ordered. See this question for an up-to-date answer
By definition, the order of keys in an object is undefined, so you probably won't be able to do that in a way that is future-proof. Instead, you should think about sorting these keys when the object is actually being displayed to the user. Whatever sort order it uses internally doesn't really matter anyway.
By convention, most browsers will retain the order of keys in an object in the order that they were added. So, you could do this, but don't expect it to always work:
function sortObject(o) {
var sorted = {},
key, a = [];
for (key in o) {
if (o.hasOwnProperty(key)) {
a.push(key);
}
}
a.sort();
for (key = 0; key < a.length; key++) {
sorted[a[key]] = o[a[key]];
}
return sorted;
}
this function takes an object and returns a sorted array of arrays of the form [key,value]
function (o) {
var a = [],i;
for(i in o){
if(o.hasOwnProperty(i)){
a.push([i,o[i]]);
}
}
a.sort(function(a,b){ return a[0]>b[0]?1:-1; })
return a;
}
The object data structure does not have a well defined order. In mathematical terms, the collection of keys in an object are an Unordered Set, and should be treated as such.
If you want to define order, you SHOULD use an array, because an array having an order is an assumption you can rely on. An object having some kind of order is something that is left to the whims of the implementation.
Just use sorted stringify() when you need to compare or hash the results.
// if ya need old browser support
Object.keys = Object.keys || function(o) {
var result = [];
for(var name in o) {
if (o.hasOwnProperty(name))
result.push(name);
}
return result;
};
var o = {c: 3, a: 1, b: 2};
var n = sortem(o);
function sortem(old){
var newo = {}; Object.keys(old).sort().forEach(function(k) {new[k]=old[k]});
return newo;
}
// deep
function sortem(old){
var newo = {}; Object.keys(old).sort().forEach(function(k){ newo[k]=sortem(old[k]) });
return newo;
}
sortem({b:{b:1,a:2},a:{b:1,a:2}})
Here is a one-liner for you.
Array.prototype.reduce()
let data = {
method: 'artist.getInfo',
artist: 'Green Day',
format: 'json',
api_key: 'fa3af76b9396d0091c9c41ebe3c63716'
};
let sorted = Object.keys(data).sort().reduce( (acc, currValue) => {
acc[currValue] = data[currValue];
return acc;
}, {});
console.log(sorted);
Good luck!!
ES5 Compatible:
function sortByKey(obj) {
var keys = Object.keys(obj);
keys.sort();
var sorted = {};
for (var i = 0; i < keys.length; i++) {
var key = keys[i];
sorted[key] = obj[key];
}
return sorted;
}
This should be used with caution as your code shouldn't rely on Object properties order. If it's just a matter of presentation (or just for the fun !), you can sort properties deeply like this :
function sortObject(src) {
var out;
if (typeof src === 'object' && Object.keys(src).length > 0) {
out = {};
Object.keys(src).sort().forEach(function (key) {
out[key] = sortObject(src[key]);
});
return out;
}
return src;
}
I have 2 arrays namely,
configdata = ["assignee", "shortDesc"];
ticketarray = ["Tom","testDesc"];
I want to store the values as a key value pair in another array, something like this:
ticketData = ["assignee":"Tom","shortDesc":"testDesc"];
Kindly note that the array values are dynamic, so I cannot hardcode them.
Is there a way to do so? I am able to achieve the above said requirement but the length always shows 0. This is the code that I am using:
configdata.Incident_Field.forEach(function (k, i) {
this[k] = ticketarray[i];
}, ticketData);
Other people have explained why your code did not work. I am providing another solution using reduce.
const configdata = ["assignee", "shortDesc"];
const ticketarray = ["Tom", "testDesc"];
let ticketData = configdata.reduce((result, value, index) => {
result[value] = ticketarray[index];
return result;
}, {});
console.log(ticketData);
Output:
{
assignee: "Tom",
shortDesc: "testDesc"
}
The below is not a valid structure in JavaScript:
ticketData = ["assignee":"Tom","shortDesc":"testDesc"];
What you need is a JavaScript object. The best you can do is:
Make sure both the array lengths are same.
Associate the key and value by creating a new object.
Use Object.keys(obj).length to determine the length.
Start with the following code:
configdata = ["assignee", "shortDesc"];
ticketarray = ["Tom", "testDesc"];
if (configdata.length == ticketarray.length) {
var obj = {};
for (var i = 0; i < configdata.length; i++)
obj[configdata[i]] = ticketarray[i];
}
console.log("Final Object");
console.log(obj);
console.log("Object's Length: " + Object.keys(obj).length);
The above will give you an object of what you liked, a single variable with all the values:
{
"assignee": "Tom",
"shortDesc": "testDesc"
}
Very similar to this question:
Javascript: how to dynamically create nested objects using object names given by an array
Instead of calling
assign(obj, keyPath, value)
example of usage of the previously answer:
var accountinfo = {}
assign(accountinfo, ["name", "addressinfo", "zipcode"], "90210");
That will output:
accountinfo = {name: "", addressinfo: {zipcode:"90210"}};
Now, I'd like to support arrays... in the above example, I'd like to support multiple addressinfo per account. I'd like to say:
assign(accountinfo, ["name", "addressinfo[1]", "zipcode"], "90210");
The result would be:
accountinfo = {name: "", addressinfo: [{},{zipcode:"90210"}]}
var regex = /\[([0-9]+)\]/ will show me the # inside the brackets, but I'm not sure how I'd have to iterate through each element in the array to make sure it exists (and create it if it doesn't).. and the difficult part, support this for each array element submitted as part of the function (I'd like to say :
assign(accountinfo, ["family", "name[3]", "addressinfo[1]", "zipcode"], "90210");
Edit:
Figured it out.
function assign(obj, keyPath, value) {
keyPath = keyPath.split(‘.’);
lastKeyIndex = keyPath.length - 1;
var re = /^(.+?)\[*(\d+)*\]*$/;
for (var i = 0; i < lastKeyIndex; i++) {
key = keyPath[i];
var ind;
var middle = re.exec(key);
key = middle[1];
ind = middle[2];
if (ind) {
if (!(obj[key]))
obj[key] = [];
if (!(obj[key][ind]))
obj[key][ind] = {};
}
if (!(key in obj))
obj[key] = {};
if (ind)
obj = obj[key][ind];
else
obj = obj[key];
}
obj[keyPath[lastKeyIndex]] = value;
}
I have the following object:
var input = {
"document": {
"people":[
{"name":"Harry Potter","age":"18","gender":"Male"},
{"name":"hermione granger","age":"18","gender":"Female"}
]
}
}
I do like this :
_.each(result.document[people], function(item){
console.log(item);
//What should I do here ? or I come wrong way ?
});
And in item I get :
{name : 'Harry Potter', age : '18':, gender:'Male'}
{name : 'hermione grange', age : '18':, gender:'Female'}
I would like to get [name,age,gender]. What should I do?
If you think your values are dynamic use a function first
var input = {
"document": {
"people":[
{"name":"Harry Potter","age":"18","gender":"Male"},
{"name":"hermione granger","age":"18","gender":"Female"}
]
}
}
var func = function (one, two) {
var array = input[one][two];
var arr =[];
for (var i=0; i<array.length; i++){
arr = Object.keys(array[0]);
}
return arr;
}
func("document", "people"); // will return ["name", "age", "gender"]
Try this
var s = {name: "raul", age: "22", gender: "Male"}
var keys = [];
for(var k in s) keys.push(k);
Here keys array will return your keys ["name", "age", "gender"]
Something like this?
_.each(result.document[people], function(item) {
_.each(item, function(item, key) {
console.log(key);
});
});
_.each sends in a second key parameter to the callback function in the case of objects.
OK, Now I know you actually want the name of object, not the value. So I add another code for you.
I'm sorry I don't have time to explain now, but this code I wrote does the trick you need.
This shows the name of object:
root_obj=input.document.people[0];
tmp=[];
for(val in root_obj )
{
tmp.push(val);
}
console.log(tmp);
This shows the value of object:
root_obj=input.document.people;
for(obj in root_obj )
{
tmp=[];
for(val in root_obj[obj] )
{
tmp.push(root_obj[obj][val]);
}
console.log(tmp);
}
Here you go.. Final answer. (edited to return keys instead of values as per comment)
_.each(result.document[people], function(item){
//get keys as numerical array
var num_arr = [];
for (var key in item) {
num_arr.push( key );
}
console.log(num_arr); // should return ['name', 'age', 'gender']
});
Not sure if the title of the question is doing it justice, but here is an example. I have object:
var plumber = {
name: 'Mario',
age: 42,
game: 'Super Mario'
}
I am looking for an elegant way of using either jQuery or Undescore to get key and value from this object.
// foo() would be desired elegant function
plumber.foo('name')
#> { name: 'Mario' }
// or even better
plumber.foo(['name','age'])
#> { name: 'Mario', age: 16 }
Thank you!
Underscore.js has _.pick that does exactly that:
var new_obj = _.pick(obj, ['name', 'age']);
I think you could approach this two ways (without either of those two libraries). You can either pass the function an array of keys or you could pass it a variable number of arguments.
fiddle
Using an array
var plumber = {
name: 'Mario',
age: 42,
game: 'Super Mario'
}
var splitObject = function (obj, keys) {
var holder = {};
keys.forEach(function (d) {
holder[d] = obj[d];
})
return holder;
}
var example = splitObject(plumber, ["name", "age"]);
console.log("example #1", example);
Using a variable number of arguments
var variableArguments = function (obj) {
var keys = Array.prototype.slice.apply(arguments).slice(1),
holder = {};
keys.forEach(function (d){
holder[d] = obj[d];
})
return holder;
}
var example2 = variableArguments(plumber, "name", "age");
console.log("example #2", example2);
Underscore.js probably has its own function for this. You'd have to check the documentation.
edit:
pick is probably the most appropriate function, as per the comments above.
Not sure what exactly you're trying to accomplish here, as your first example could be accomplished easily by calling:
plumber.name;
if you were unsure of what the input would be, and needed to pass a variable, you can do it like this:
var arg = 'name';
plumber[arg];
Your second example is a little more complex, for these purposes I'm going to assume you want to be able to pass an arbitrary array of keys and return an object containing the key/value pairs for each one. If you are comfortable with prototyping global objects, you could do this:
Object.prototype.getValuesFromKeys = function (keys) {
var ret = {};
for (var i = 0; i < arr.length; i++) {
ret[keys[i]] = this[keys[i]];
}
return ret;
};
plumber.getValuesFromKeys(['name','age']);
If you want that functionality without prototyping the global Object, you could build it this way instead:
function getValuesFromKeys(obj, keys) {
var ret = {};
for (var i = 0; i < arr.length; i++) {
ret[keys[i]] = obj[keys[i]];
}
return ret;
};
getValuesFromKeys(plumber, ['name','age']);