The replace method supports the nesting of a function in place of the second argument. New method toSource. The toSource method returns a string representing the source code of the object. See Array.toSource , Boolean.toSource , Date.toSource , Function.toSource , Number.toSource , Object.toSource , RegExp.toSource , and String.toSource . New top-level properties Infinity, NaN, and undefined.
Infinity is a numeric value representing infinity.
New top-level function isFinite. Changes to the top-level eval function. You should not indirectly use the eval function by invoking it via a name other than eval . If the two operands are not of the same type, JavaScript attempts to convert the operands to an appropriate type for the comparison. Changes to the behavior of conditional tests.