JSFiddle - React, Tailwind, and code Playground
HTML
<div id="arr1"></div>
<br>
<div id="arr2"></div>
JavaScript
var arr1 = [{name: "lang", value: "English"},{name: "age", value: "18"}];
var arr2 = [{name : "childs", value: '5'}, {name: "lang", value: "German"}];
//Array.prototype.push.apply(arr1,arr2);
arr1.concat(arr2);
document.getElementById("arr1").innerHTML=JSON.stringify(arr1);
document.getElementById("arr2").innerHTML=JSON.stringify(arr2);