Update Interfaces.md (zhongsp#224)

njleonzhang · zhongsp · commit 2f92532df416 · 2018-09-01T06:12:35.000+08:00
diff --git a/doc/handbook/Interfaces.md b/doc/handbook/Interfaces.md
@@ -468,7 +468,7 @@ interface Counter {
 }
 
 function getCounter(): Counter {
-    let counter = <Counter>function (start: number) { };
+    let counter = <Counter>function (start: number): string { return '' };
     counter.interval = 123;
     counter.reset = function () { };
     return counter;

Original file line number	Diff line number	Diff line change
`@@ -468,7 +468,7 @@ interface Counter {`
`468`	`468`	`}`
`469`	`469`
`470`	`470`	`function getCounter(): Counter {`
`471`		`- let counter = <Counter>function (start: number) { };`
	`471`	`+ let counter = <Counter>function (start: number): string { return '' };`
`472`	`472`	`counter.interval = 123;`
`473`	`473`	`counter.reset = function () { };`
`474`	`474`	`return counter;`