76 lines
1.8 KiB
Markdown
76 lines
1.8 KiB
Markdown
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---
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title: Create a Stack Class
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---
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## Create a Stack Class
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### Method:
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- Stack is an abstract data structure.
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- Stack follows LIFO/FILO principle.
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- In this challenge, we need to add `.push()`, `.pop()`, `.peek()`, `.isEmpty()` and `.clear()` methods to the class.
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-
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- `push()` method pushes value to the stack.
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- `pop()` method pops the first value from the stack.
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- `peek()` method returns the first value from the stack.
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- `isEmpty()` method checks if ths stack is empty.
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- `.clear()` method removes all the elements from the stack.
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-
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| DS | Access | Search | Insert | Delete |
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| ----- | ------ | ------ | ------ | ------ |
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| Stack | n | n | 1 | 1 |
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### Solution:
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#### Basic:
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```js
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function Stack() {
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var collection = [];
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this.print = function() {
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console.log(collection);
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};
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this.push = function(val){
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return collection.push(val);
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}
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this.pop = function(){
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return collection.pop();
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}
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this.peek = function(){
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return collection[collection.length-1];
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}
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this.isEmpty = function(){
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return collection.length === 0;
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}
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this.clear = function(){
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collection.length = 0;
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}
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}
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```
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#### Advanced - ES6 Class syntax:
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```js
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class Stack {
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constructor() {
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this.collection = [];
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}
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print(){
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console.log(this.collection);
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}
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push(val){
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retiurn this.collection.push(val);
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}
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pop(){
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return this.collection.pop();
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}
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peek(){
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return this.collection[this.collection.length-1];
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}
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isEmpty(){
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return this.collection.length === 0;
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}
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clear(){
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return this.collection.length = 0;
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}
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}
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```
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### Resources:
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- [Wikipedia](https://en.wikipedia.org/wiki/Stack_(abstract_data_type))
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