The use of wrapper objects for primitive types is gratuitous, confusing and dangerous. If you use a wrapper object constructor for type conversion, just remove the new keyword, and you'll get a primitive value automatically. If you use a wrapper object as a way to add properties to a primitive, you should re-think the design. Such uses are considered bad practice, and should be refactored.

Noncompliant Code Example

let x = new Number("0");
if (x) {
  alert('hi');  // Shows 'hi'.
}

Compliant Solution

let x = Number("0");
if (x) {
  alert('hi');
}

Exceptions

Cases when argument of primitive type constructor is a literal of the same type are ignored, except new Boolean(false).

let booleanObject = new Boolean(true);
let numberObject = new Number(0);
let stringObject = new String('');