JSFiddle - React, Tailwind, and code Playground

by Andrey

JavaScript

var arr1=[3,4,5,6,7];
var arr2=[1,7,90,900,9000,9009, 10000];
var arr3=[1,3,4,5,6,7,7,90,900,9000,9009,10000];

const mergeArray = (a1, a2) =>{
    let i2 = 0;

   while(a1.length) {
   	const currentItem = a1.shift();
   
    while(i2<a2.length) {
    	if(currentItem <= a2[i2]) {
      	a2.splice(i2, 0, currentItem);
        i2++;
        break;
      }
      i2++;
    }
   }
   return a2;
}

console.log(mergeArray(arr1, arr2), arr3);