Jscript with Notes

1. Jscript cannot be used to write standalone applications, and there is no built-in support for read-write files. 2. Note that the original statement in the statement block ends with a semicolon, but the statement block itself does not end with a semicolon. 3. Note that Jscript differs from C + + and some other languages in that it does not consider a statement block to be a new scope; only the function creates a new scope. 4 . Note If you try to insert a multiline comment into another, JScript cannot interpret the resulting multiline comment in a normal way. Marking the end of an embedded multiline comment is considered to be the end of the entire multiline comment. This means that text that is inserted after a multiline comment is no longer considered a comment, and, accordingly, it is interpreted as a JScript code and produces a syntax error.
5 . If there is no initialization variable in the VAR statement, the variable automatically takes the JScript value undefined . Although not secure, it is legitimate to omit the var keyword from the declaration statement . At this point, the JScript interpreter gives the variable global scope visibility. When a variable is declared at the procedure level, it cannot be used for global scope, in which case the variable declaration must use the var keyword.
6. The type of the JScript variable corresponds to the type of value they contain, and is a free-type language. Its variables do not have a predetermined type.

arithmetic	Results
Add value to String	Casts a numeric value to a string.
Adding a Boolean value to a string	Casts a Boolean value to a string.
Adding values to Boolean values	Casts a Boolean value to a number.

7. Jscript provides 11 internal (or "built-in") objects. They are Array、 Boolean、 Date、 Function、 Global、 Math、 Number、 Object、 RegExp、 ErrorAnd StringObject.
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Jscript with Notes