simpify simple array to stack!

Author: sangtrandev00

src/data_structure/stack/stack-array-implement.ts

@@ -1,55 +1,24 @@
-class Node {
-    value: any;
-    next: any;
-    constructor(value: any) {
-        this.value = value;
-        this.next = null;
-    }
-}
 
 class Stack {
     array: any = []
-    top: any;
-    bottom: any;
-    length: number;
     constructor() {
-        this.top = null;
-        this.bottom = null;
-        this.length = 0;
     }
 
     peek() {
-        if (this.length == 0) return null
-        return this.top
+        if (this.array.length == 0) return null
+        return this.array[this.array.length - 1]
     }
 
     push(value: any) {
         this.array.push(value)
-        if (this.length === 0) {
-            this.top = this.array[0]
-            this.bottom = this.array[0]
-        } else {
-            this.top = this.array[this.length]
-        }
-        this.length++
-
     }
 
     pop() {
-        if (this.length == 0) return null
-        const remove = this.array.pop()
-        if (this.length == 0) {
-            this.bottom = null
-            this.top = null
-        } else {
-            this.top = this.array[this.array.length - 1]
-        }
-        this.length--
-        return remove
+        return this.array.pop()
     }
 
     isEmpty() {
-        return this.length === 0
+        return this.array.length === 0
     }
 
     //isEmpty