JSFiddle - React, Tailwind, and code Playground

JavaScript

var arrOfStrs = ["1","2","3","4"];
var arrObj1 = [];

for(var i = 0 ; i < arrOfStrs.length; i++)
{
    arrObj1.push({item: arrOfStrs[i]});
}

console.log(arrObj1);

var arrObj2 = [];
for(var key in arrOfStrs)
{
    arrObj2.push({item: arrOfStrs[key]});
}
                 
console.log(arrObj2);