how to declare a var in js code example

Example 1: javascript declare a variable

//choose the best for your solution
var myVariable = 22; //this can be a string or number. var is globally defined

let myVariable = 22; //this can be a string or number. let is block scoped

const myVariable = 22; //this can be a string or number. const is block scoped and can't be reassigned

Example 2: js var

var a;
console.log(a);                // scrive in console "undefined" o "" a seconda del browser usato.
console.log('still going...'); // scrive in console "still going...".