Question

I am adding a new field in one of my web apps, for visitors to add a product. Pushing “add a product” clones one of the existing inputs, and I set it to a blank value.

I need to update the name however. The name is in this format:

<input type="text" name="product[0][0][3][title]" value="my product" id="input-AbGHtQS3" maxlength="150" />

I need to increment the last numerical index, that is the 3 in this example.

I wrote a regex to match the appropriate character, but how can I increment that last number?

Here is my regex:

/^product\[\d+\]\[\d+\]\[(\d+)\]\[.+\]/

How could I increment that last number?

Answer 1

from: Use RegExp to match a parenthetical number then increment it

The replace method can take a function as its second argument. It gets the match (including submatches) and returns the replacement string. Others have already mentioned that the parentheses need to be escaped.

"Item Name (4)".replace(/\((\d+)\)/, function(fullMatch, n) {
    return "(" + (Number(n) + 1) + ")";
});

So,

*edit:

this should work

"product[0][0][3][title]".replace(/(^product\[\d+\]\[\d+\]\[)(\d+)(\]\[.+\])/, function(fullMatch, n, a, o) {
    return n + (Number(a) + 1) + o;
});