Javascript equivalent of Python's values() dictionary method [duplicate]
In Python I can use the .values()
method to iterate over the values of a dictionary.
For example:
mydict = {'a': [3,5,6,43,3,6,3,],
'b': [87,65,3,45,7,8],
'c': [34,57,8,9,9,2],}
values = mydict.values():
Where values
contains:
[
[3,5,6,43,3,6,3,],
[87,65,3,45,7,8],
[34,57,8,9,9,2],
]
How can I get only the values of the dictionary in Javascript?
My original print example wasn't clear on what I'd like to do. I only want a list/array of the values within the dictionary.
I realize I can cycle through the list and create a new list of the values, but is there a better way?
Solution 1:
Updated
I've upvoted Adnan's answer as it was the first. I'm just posting a bit more details if it helps.
The for..in loop is what you are looking for -
var dictionary = {
id:'value',
idNext: 'value 2'
}
for (var key in dictionary){
//key will be -> 'id'
//dictionary[key] -> 'value'
}
To get all the keys in the dictionary
object, you can Object.keys(dictionary)
This means, you can do the same thing in an array loop --
var keys = Object.keys(dictionary);
keys.forEach(function(key){
console.log(key, dictionary[key]);
});
This proves especially handy when you want to filter keys without writing ugly if..else
loops.
keys.filter(function(key){
//return dictionary[key] % 2 === 0;
//return !key.match(/regex/)
// and so on
});
Update - To get all the values in the dictionary, currently there is no other way than to perform a loop. How you do the loop is a matter of choice though. Personally, I prefer
var dictionary = {
a: [1,2,3, 4],
b:[5,6,7]
}
var values = Object.keys(dictionary).map(function(key){
return dictionary[key];
});
//will return [[1,2,3,4], [5,6,7]]
Solution 2:
Object.values() is available in Firefox 47 and Chrome 51, here's a one-line polyfill for other browsers:
Object.values = Object.values || function(o){return Object.keys(o).map(function(k){return o[k]})};
Solution 3:
With jQuery, there's a pretty one line version using $.map():
var dict = {1: 2, 3: 4};
var values = $.map(dict, function(value, key) { return value });
var keys = $.map(dict, function(value, key) { return key });
Solution 4:
Not trying to say that any of the other answers are wrong, but if you're not opposed to using an external library, underscore.js has a method for precisely this:
_.values({one: 1, two: 2, three: 3});
// returns [1, 2, 3]