JavaScript subtracting values in arrays

[danielpybus]

Hi all, please note I am very much a beginner lol. And I have run into a bit of a snag.

var stockBlock = ['abc', 123, 500, 500, 2000];
var jobBlock = ['def', 123, 100, 100, 300];

I have these two arrays in my javascript. I want to subtract one value of jobBlock (index 4 - 300) from index 4 of stockBlock (2000) and create a new array as follows:

var residueBlock = [ghi, 123, 500, 500, 1700];

But I have no idea how. I have tried using .splice, but all that does is display the removed element (2000). I really am very lost. Any guidance would be greatly appreciated.

Thank You

 

[ivan.moony]

Maybe you could try:

var residueBlock = ['ghi', stockBlock[1], stockBlock[2], stockBlock[3], stockBlock[4] - jobBlock[4]]

 

[danielpybus]

Thank you so much, that worked perfectly!

 

[ivan.moony]

You can also try:

var residueBlock = [...stockBlock]; // this clones the stockBlock array
residueBlock[0] = "ghi"; // updates the zeroth element of residueBlock
residueBlock[4] = residueBlock[4] - jobBlock[4]; // updates the fourth element of residueBlock

 

[Malcolm]

Hi all, please note I am very much a beginner lol. And I have run into a bit of a snag.

var stockBlock = ['abc', 123, 500, 500, 2000];
var jobBlock = ['def', 123, 100, 100, 300];

I have these two arrays in my javascript. I want to subtract one value of jobBlock (index 4 - 300) from index 4 of stockBlock (2000) and create a new array as follows:

var residueBlock = [ghi, 123, 500, 500, 1700];

But I have no idea how. I have tried using .splice, but all that does is display the removed element (2000). I really am very lost. Any guidance would be greatly appreciated.

Thank You

Hi there,

Welcome to Code Forum!

I see @ivan.moony was able to help you. Make sure to mark his post as a solution if it solved your issue if not and you found it elsewhere then please post it here to help others.

And, for future reference, please use our BBCode feature before posting any code. It makes it easier to read and copy when you do use this feature. You can view more information about our BBCode here.

 

[danielpybus]

Thank you, I will look into BBCode.

Instead of making another post, can I add a question here?

I have two csv files I have read with javascript and converted them into arrays. I want to compare values between them eg if the value of index[3] row 1 of the first array is bigger/smaller than index[3] row 1 of the second array, then.......etc etc. But how do you specify which array? They are not named? Do I need to merge them?

Appreciate the help