Split Array value into 2nd Array inside the current array

Question

So I have an array with the following values.

var keyVal = ["John, 2","Jane, 2", "John, 4","Jane, 5" ];

I'm trying to break out the array values into 2 it's own array so it would look like this.

var keyVal = [["John"][2],["Jane"][2], ["John"][2],["Jane"][2]];

I tried using a for loop like this:

for (var i=0; i< keyVal.length; i++ ){
 keyVal[i].split(",");
 }

But for some reason when I go to check, nothing is changing.... What am I missing?

Thanks for your help!

• Ryan: May I suggest a new data structure?

Answer 1

According to MDN, the .split method creates a new array with strings and doesn't affect the value of the original string, so you must update the value of each item of the array:

for (var i=0; i< keyVal.length; i++ ){
 keyVal[i] = keyVal[i].split(",");
}

• Cerbrus: "the .split method creates new String instances" What? You may need to clarify that a bit more.
• Danilo Valente: @Cerbrus I meant that it creates a new array with strings and doesn't affect the value of the original string.

Answer 2

You're just missing the assignment in your loop:

for (var i=0; i< keyVal.length; i++ ){
 keyVal[i] = keyVal[i].split(",");
}

This will result in:

keyVal == [["John"," 2"],["Jane"," 2"],["John"," 4"],["Jane"," 5"]]

• Jason Griffith: Thank you so much! Too close to the forest to see the trees I suppose.