Comparing JSON array with user input and get a value

Question

I am building some kind of calculator where the user can input his income and then the function iterates on a JSON array to find the according number. It should be something like:

if (z >= x && z <= y)

Where z is the user input and x and y are the limits on both sides.

Here is the JSON array (only 3 out 100):

[["0",0],["1",898],["2",12654],["3",15753]]

I don't know how to write this function. I could do it using 100 ifs and elseifs though. But I am pretty sure there is a nicer way.

ShaneQful · Accepted Answer · 2015-08-04 10:24:32Z

2

Essentially you need to loop through each of the bounds to find where the persons income is e.g.

function getIncomeBound(input) {
    //Note: this is not the best way to store this data but that's another issue
    var bounds = [["0",0],["1",898],["2",12654],["3",15753]];
    var out = bounds[0];
    bounds.forEach(function (el, idx) {
        out = (idx !== 0 && input <= el[1] && input > bounds[idx - 1][1] ? el : out);
    });
    return out;
}

Explanation:

Set a variable out which will be our return value to the first bound
Loop through the bounds and if the input is lower than the current bound and higher than the previous we set it to be the out value (Note: we skip over the first iteration with idx !== 0 as we have set this as the out value already)
By this method we should arrive at the bound which the input is in between and we return this value

edited Aug 4, 2015 at 10:24

answered Aug 4, 2015 at 10:18

ShaneQful

2,2862 gold badges18 silver badges24 bronze badges

Sign up to request clarification or add additional context in comments.

5 Comments

Felix Over a year ago

Thanks for your answer. I'll try to set i up and create a fiddle. I also need to pass some more information once the right bound is found.

Felix Over a year ago

right now it puts out both values 1 and 898, putting them together to 1898

Felix Over a year ago

ok now it works. How can i set the limit? for the highest amount? For the last / highest entry in the array?

ShaneQful Over a year ago

Well the function assumes at the moment that your input it within the bounds of the array you could do an if statement before the function or somewhere within the function to check the bounds e.g. if (input > bounds[bounds.length -1][1]) {return null;} where null is the value your expect back if it's not within the bounds.

ShaneQful Over a year ago

Also as it's a correct answer do you mind marking it as so ?

Collectives™ on Stack Overflow

Comparing JSON array with user input and get a value

1 Answer 1

5 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

5 Comments

Your Answer

Sign up or log in

Post as a guest

Related