Merge pull request #13 from kennarddh/feat/Stack

Stack

Author: devvsakib

L-I/0003 Stack ( L-I )/README.md

@@ -0,0 +1,52 @@
+# 0003 Stack ( L-I )
+
+## Problem
+
+Create a class that has 3 method and 1 property.
+
+-   Push method add new element to the stack
+-   Pop method remove last added element and return removed element
+-   Peek return last added element
+-   Size property return stack size
+
+## Solution
+
+```javascript
+class Stack {
+	constructor() {
+		this.stack = []
+	}
+
+	push(value) {
+		this.stack.push(value)
+	}
+
+	pop() {
+		return this.stack.pop()
+	}
+
+	peek() {
+		return this.stack.at(-1)
+	}
+
+	get size() {
+		return this.stack.length
+	}
+}
+```
+
+## References
+
+-   [Class MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes)
+-   [Stack GeeksForGeeks](https://www.geeksforgeeks.org/implementation-stack-javascript/)
+-   [Array MDN](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)
+
+## Problem Added By
+
+-   [GitHub](https://www.github.com/kennarddh)
+
+## Contributing
+
+Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.
+
+Please make sure to update tests as appropriate.

L-I/0003 Stack ( L-I )/Stack.js

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+class Stack {
+	constructor() {
+		this.stack = []
+	}
+
+	push(value) {
+		this.stack.push(value)
+	}
+
+	pop() {
+		return this.stack.pop()
+	}
+
+	peek() {
+		return this.stack.at(-1)
+	}
+
+	get size() {
+		return this.stack.length
+	}
+}
+
+module.exports = Stack

L-I/0003 Stack ( L-I )/Test.js

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+const { strict: assert } = require('assert')
+
+const Stack = require('./Stack.js')
+
+const stack = new Stack()
+
+stack.push('foo')
+
+assert.equal(stack.size, 1)
+
+stack.push('bar')
+
+assert.equal(stack.size, 2)
+
+assert.equal(stack.peek(), 'bar')
+assert.equal(stack.size, 2)
+assert.equal(stack.pop(), 'bar')
+assert.equal(stack.size, 1)
+assert.equal(stack.peek(), 'foo')
+assert.equal(stack.size, 1)
+
+stack.push('foobar')
+
+assert.equal(stack.size, 2)
+assert.equal(stack.peek(), 'foobar')
+assert.equal(stack.size, 2)
+assert.equal(stack.pop(), 'foobar')
+assert.equal(stack.size, 1)
+assert.equal(stack.pop(), 'foo')
+assert.equal(stack.size, 0)
+
+console.log('All tests success')