Why does typeof 3>2 return false in javascript console?

Question

The following link provides a description and examples about how typeof works: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/typeof

Answer 1

In JavaScript the operator "typeof" has a precedence of 4 while the operator greater ">" than has a precedence of 8, so according to the example mentioned in the question typeof 3 gets evaluated first and then compared to 2 which returns false.

More details can be found about precedence and associativity of operators at: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Operator_Precedence

Answer 2

To explain what's going on, the interpreter treats it as:

(typeof 3) > 2

The typeof operator always returns a string, and 3 is a number so the expression resolves to:

'number' > 2

The Greater-than Operator ( > ) applies the Abstract Relational Comparison Algorithm to get the result of the comparison. Since 'number' is a String, it's converted to a Number using the internal ToNumber operation (step 3a). A string that doesn't contain a number literal (e.g. "3") results in NaN (see note below), so now the expression is:

NaN > 2

Step 3c says if the left hand expression is NaN, return undefined (that is, the special undefined value, not the string 'undefined').

So undefined is returned, and step 6 of the greater–than operator algorithm says:

If [the result] is undefined, return false. Otherwise, return [the result].

so ultimately, the expression returns false.

Note: a string containing only whitespace (one or more spaces, tabs, newlines, etc.) converts to the number 0, which is the only case where a string that isn't a numeric literal converts to a number value other than NaN. See ToNumber Applied to the String Type.

Answer 3

Because typeof 3 is not more than 2.

You need parentheses.