target json use the value of a variable javascript code example

Example 1: how to change a variables value in javascript

var variable = 10;

function start() {
  variable = 20;
}
console.log(variable + 20);

// Answer will be 40 since the variable was changed in the function

Example 2: how to get value in array object value using for loop in javascript

const people = [
    {name: 'John', age: 23}, 
    {name: 'Andrew', age: 3}, 
    {name: 'Peter', age: 8}, 
    {name: 'Hanna', age: 14}, 
    {name: 'Adam', age: 37}];

const anyAdult = people.some(person => person.age >= 18);
console.log(anyAdult); // true

Example 3: how to change input value in javascript using class

// Find the input element with a class of "bar" that is a direct child of a form with a name attribute of "foo"
document.querySelector("form[name='foo'] > input.bar").value = "hehe works"