RegExp with search() method
The search() method will return a value of the index within the string of the first occurrence that matches the pattern, if no match is found then the result will return a value of -1. You can use the i flag within the regular expression to match on the pattern regardless of the case of the letters. I – case-insensitive making the pattern case-insensitive.

search() method

const txtArea = document.querySelector(‘textarea’);

const btn = document.querySelector(‘button’);

const res = document.querySelector(‘.results’);

const str1 = ‘Hello love World.  I love JavaScript!’;

const reg = /love/i;

txtArea.value = str1;

btn.addEventListener(‘click’,()=>{

   const str =  txtArea.value;

   const rep = str.search(reg);

   if(rep == -1){

       res.textContent = `Result ${reg} not found in the string!`;

   }else{

       res.textContent = `Result ${reg} found at index value ${rep}`;

   }

   console.log(rep);

})