JSLint -Tolerate Ineffective Subscription?

Question

I read the JSlint Options Documentation to understand each of the available options and stumbled upon the fact that I do not quite understand and cannot find any useful information about this elsewhere.

sub - Assume inefficient subpitting

true if the index notation can be used for expressions that are more expressed in dotted notation.

Can anyone shed more light on what this means?

thanks

Answer 1

JavaScript objects can be accessed using a descriptor (square bracket):

o.foo o['foo'] 

... This is the same. A square bracket is necessary to access members whose names cannot be used in dotted notation:

 o['hello!'] 

or to access members from a dynamic name:

 var name= issomething? 'foo' : 'bar'; o[name] 

But for simple o['foo'] you do not need it. The o.foo form is o.foo easier to read, so she thinks it's best to use it. Some programmers coming from other languages ​​may prefer to use square brackets for objects that use “as a match, not as,” but anyway for JS.

(JSlint claims that the shape of the square bracket is also “less efficient,” but if that is the case, the difference is tiny and really not worth the worry.)

Answer 2

See here . It looks like the notation in the subscript does:

 document.forms['myformname']; 

instead

 document.forms.myformname;