know type of a variable in javascript code example

Example 1: javascript find type of variable

> typeof "foo"
"string"
> typeof true
"boolean"
> typeof 42
"number"

if(typeof bar === 'number') {
   //whatever
}

Example 2: node js check type of variable

if (typeof i != "number") {
    console.log('This is not number');
}

Example 3: javascript get type of var

typeof operando