render (h) {
Const component=(
Role="menubar 
"Key={+ enclosing the collapse} 
Style={{backgroundColor: enclosing backgroundColor | | '}} 
Class={{
'el - menu -- horizontal' : this mode==='horizontal', 
'el - menu - the collapse: enclosing the collapse, 
"El - menu" : true 
}} 
 
{this. $slots. The default} 
 
); 

If (this. CollapseTransition) {
Return (
 
{component} 
 
); 
} else {
Return component; 
} 
} 

Boring to see the next elementUI source, found that a previously unknown parentheses () grammar, such as the above
Component=(* * * *)
Have a little meng this is the string?

CodePudding user response:

This is not a legitimate javascript syntax;

This should be JSX grammar, the need to use the Babel or certain types of file loader translated into correct grammar,

CodePudding user response:

Js four brackets usage:
1. Improve the priority, (3 + 5) * 2 is not equal to 3 + 5 * 2
2. As part of the other grammar, responsible for the circle function () {} the if () (function () {}) ()
3. The execution of the function the add ()
4. Nothing is circle, look good (6)