Unary Operator

The unary + operator converts its operand to Number type.

let positiveOne = +1

You don't need to parseInt or parseFloat.

So, to convert a string or a Boolean, or a Numeric String, you can just use +.

+false  // 0  
+‘123’  // 123  
+0xBABE // 47806 (Hexadecimal)  
+null   // 0  
+function(val) {return val } // NaN

The Unary (+) can convert string representations of integers and floats, as well as the non-string values true, false, and null. Integers in both decimal and hexadecimal formats are supported. Negative numbers are supported (though not for hex). If it cannot parse a particular value, it will evaluate to NaN.

However, bear in mind that the Unary (+) does not perform well in certain cases. For example, it doesn't work as expected on empty strings, alphanumeric strings, empty objects etc.

+''     // NaN  
+'123a' // NaN  
+{}     // NaN

Links

1. Nullish Coalesning operator