Automatic conversion to a string

Explains how nonstrings are automatically converted to strings.

When a function or a method that expects a string as one of its arguments is passed a nonstring value, this value is automatically converted to a string. For example, if the string method indexOf is passed a number as its first argument, this number is treated like its string representation:

"The 10 commandments".indexOf(10) -> 4

Similarly, operators that take string operands automatically convert nonstring operands to strings:

"The " + 10 + " commandments" -> "The 10 commandments"

The conversion to a string uses the toString method of the given value. All built-in values have a toString method.