JSFiddle - React, Tailwind, and code Playground
JavaScript
var arr = ["Есть", "жизнь", "на", "Марсе"];
js = arr.map(function(leng){
console.log(leng.length);
});
//
add = [ 1, 2, 3, 4, 5 ];
var jx = add.reduce(function(sum,current){
return sum + current
},0)
console.log(jx)