Number.prototype.toString ( [ radix ] )

NOTEThe optional radix should be an integer value in the inclusive range 2 to 36. If radix not present or is undefined the Number 10 is used as the value of radix.

The following steps are performed:

1. Let x be thisNumberValue(this value).

2. ReturnIfAbrupt(x).

3. If radix is not present, let radixNumber be 10.

4. Else if radix is undefined, let radixNumber be 10.

5. Else let radixNumber be ToInteger(radix).

6. ReturnIfAbrupt(radixNumber).

7. If radixNumber < 2 or radixNumber > 36, throw a RangeError exception.

8. If radixNumber = 10, return ToString(x).

9. Return the String representation of this Number value using the radix specified by radixNumber. Letters a-z are used for digits with values 10 through 35. The precise algorithm is implementation-dependent, however the algorithm should be a generalization of that specified in 7.1.12.1.

The toString function is not generic; it throws a TypeError exception if its this value is not a Number or a Number object. Therefore, it cannot be transferred to other kinds of objects for use as a method.