Spec.md

String Trim Functions

String.prototype.trim ( )

Return result of StringTrim abstract operation passing this value as thisArg, and TrimBoth as the type.

String.prototype.trimRight ( )

Return result of StringTrim abstract operation passing this value as thisArg, and TrimRight as the type.

String.prototype.trimLeft ( )

Return result of StringTrim abstract operation passing this value as thisArg, and TrimLeft as the type.

NOTE: The trim, trimLeft, and trimRight functions are intentionally generic; they do not require that their this value be a String object. Therefore, they can be transferred to other kinds of objects for use as a method.

Helper Abstract Operations

StringTrim(thisArg, type) abstract operation

This function interprets a string value as a sequence of UTF-16 encoded code points, as described in <...>.

The following steps are taken:

1. Let O be RequireObjectCoercible(thisArg).
2. Let S be ToString(O).
3. ReturnIfAbrupt(S).
4. Let T be a String value that is a copy of S with:

• if type is TrimBoth, then with both leading and trailing white space removed
• else if type is TrimRight, then with trailing white space removed
• else if type is TrimgLeft, then both leading white space removed
• NOTE: The definition of white space is the union of WhiteSpace and LineTerminator. When determining whether a Unicode code point is in Unicode general category "Zs", code unit sequences are interpreted as UTF-16 encoded code point sequences as specified in <...>.

5. Return T.