Is there some javascript function that can take a string already formatted as an array, and casts it as an array?
var some_string = "[1,2,3,4]";
var some_array = castAsArray(some_string);
some_array.length // Returns 4.
2 Answers
What you're looking for is JSON.parse(). It'll take any string that represents a valid JavaScript object in JSON (JavaScript Object Notation), and convert it to an object.
var some_string = "[1,2,3,4]";
var some_array = JSON.parse(some_string);
some_array.length // Returns 4.
1 Comment
Florian Salihovic
Life can be simple sometimes ...
Even eval will do the trick. Using eval, is not good practice but it is just a suggestion.
a="[1,2,3,4]"
b=eval(a)
Understand that using eval is always a bad idea (always means at most of the cases) and this is one excellent SO question and answers discussing this.
answered May 19, 2014 at 16:55
Jack_of_All_Trades
11.6k20 gold badges64 silver badges96 bronze badges
16 Comments
Don P
If you are going to downvote, leave a comment please. He is trying to help. @Shmiddty, it's great that you know why this is wrong, but at some point you didn't. Instead of "tsks", please explain why.
cookie monster
+1 It's a valid solution, and could be the best solution in some cases.
Sterling Archer
@Jack_of_All_Trades I didn't downvote, but just because it works, doesn't mean it's good code. Typically there is no justifiable reason to use
eval like this. Answers should provide good code, not "suggestions"
Sam Hanley
The downvote isn't mine but it's likely because JSON.parse() is the actual way to do this, and using eval() in this case accomplishes nothing but opening you up to exploits.
cookie monster
@sphanley: That's an overreaction to
eval. JSON.parse isn't "the actual way". It's one if a number of different ways. The best way to do it will depend on the overall circumstance. |
var some_array = JSON.parse(some_string);. If the actual string isn't JSON data, then a different approach will be needed.