fix: extra credit stack.ts

txtran224 · txtran224 · commit 82edf1cbc9c6 · 2024-10-23T14:40:04.000Z
diff --git a/lesson_12/structs_ts/src/stack.ts b/lesson_12/structs_ts/src/stack.ts
@@ -20,9 +20,11 @@ export class Stack {
   }
 
   peek(): number | null {
+    if (this.top === undefined) {
+      throw new Error('is Empty');
+    }
     return this.top ? this.top.val : null;
   }
-
   isEmpty(): boolean {
     return this.top === undefined;
   }

Original file line number	Diff line number	Diff line change
`@@ -20,9 +20,11 @@ export class Stack {`
`20`	`20`	`}`
`21`	`21`
`22`	`22`	`peek(): number \| null {`
	`23`	`+ if (this.top === undefined) {`
	`24`	`+ throw new Error('is Empty');`
	`25`	`+ }`
`23`	`26`	`return this.top ? this.top.val : null;`
`24`	`27`	`}`
`25`		`-`
`26`	`28`	`isEmpty(): boolean {`
`27`	`29`	`return this.top === undefined;`
`28`	`30`	`}`