ES6的JavaScript数据结构的实现

Posted 2022-12-02 xinkuiwu

目的：ES6标准下的JS数据结构的一些实现代码。（作为记录和启发）

内容：栈。（未完成，待继续）

一、数据结构

1、栈（先入后出）

// @ts-check

class Stack
constructor()
this.count = 0;
this.items = ;

push(element)
this.items[this.count] = element;
this.count++;

pop()
if (this.isEmpty())
return undefined;

this.count--;
const result = this.items[this.count];
delete this.items[this.count];
return result;

peek()
if (this.isEmpty())
return undefined;

return this.items[this.count - 1];

isEmpty()
return this.count === 0;

size()
return this.count;

clear()
/* while (!this.isEmpty())
this.pop();
*/
this.items = ;
this.count = 0;

toString()
if (this.isEmpty())
return ‘‘;

let objString = `$this.items[0]`;
for (let i = 1; i < this.count; i++)
objString = `$objString,$this.items[i]`;

return objString;


const stack = new Stack(); // new StackArray();

// using WeakMap to store Stack items we ensure true privacy
// console.log(Object.getOwnPropertyNames(stack));
// console.log(Object.keys(stack));
// console.log(stack.items);

console.log(‘stack.isEmpty() => ‘, stack.isEmpty()); // outputs true

stack.push(6);
stack.push(8);

console.log(‘stack after push 5 and 8 => ‘, stack.toString());

console.log(‘stack.peek() => ‘, stack.peek()); // outputs 8

stack.push(11);

console.log(‘stack.size() after push 11 => ‘, stack.size()); // outputs 3
console.log(‘stack.isEmpty() => ‘, stack.isEmpty()); // outputs false

stack.push(15);

stack.pop();
stack.pop();

console.log(‘stack.size() after push 15 and pop twice => ‘, stack.size());

 

2、队列