Grab substring after and before two specific characters in javascript

Question

i have a url search key like that: ?retailerKey=A and i want to grab the retailerKey substring. All examples that i saw are having as example how to take before the char with the indexOf example. How can i implement this to have this substring from the string ?retailerKey=A

Answer 1

You could split() the string on any ? or = and take the middle item ([1]) from the outcome array.

const data = "?retailerKey=A";
const result = data.split(/[\?=]/)[1];

console.log(result);

If you have multiple params, creating an object fromEntries() would be interesting.

const data = "?retailerKey=A?otherKey=B";

const keyVals = data.split(/[\?=]/).filter(x => x); // keys and values
const result = Object.fromEntries(keyVals.reduce((acc, val, i) => {
  // create entries
  const chunkI = Math.floor(i / 2);
  if (!acc[chunkI]) acc[chunkI] = [];
  acc[chunkI].push(val);
  return acc;
}, []));

console.log(result);