10.typescript-字符串字面量类型

1 // html                                                                                                        
2 <div id="div">my name is Mr.</div>

1 type name = "wei" | "ze" | "yang";
2 
3 function student(ele:Element, event:name){
4   return () => {
5     return ele.innerHTML += event;
6   };
7 }
8  
9 student(document.getElementById("div"),"wei")();

 1 type name = "wei" | "ze" | "yang";
 2 
 3 function student(ele:Element, event:name){
 4   return () => {
 5     return ele.innerHTML += event;
 6   };
 7 }
 8 
 9 student(document.getElementById("div"),"why")();
10 //  Argument of type ‘"why"‘ is not assignable to parameter of type ‘name‘.