JavaScript 設計模型 - Iterator

interface IteratorInterface {
    index: number
    dataStorage: any
    hasNext(): boolean
    next(): any
    addItem(item: any): void
}

class iterator1 implements IteratorInterface {
    index: number
    dataStorage: any[]
    constructor() {
        this.index = 0
        this.dataStorage = []
    }
    hasNext(): boolean {
        return this.dataStorage.length > this.index
    }
    next(): any {
        return this.dataStorage[this.index ++]
    }
    addItem(item: any): void {
        this.dataStorage.push(item)
    }
}

// map
class iterator2 implements IteratorInterface {
    index: number
    dataStorage: Map<number, any>
    constructor() {
        this.index = 0
        this.dataStorage = new Map<number, any>()
    }
    hasNext(): boolean {
        return this.dataStorage.get(this.index) != undefined
    }
    next(): any {
        return this.dataStorage.get(this.index ++)
    }
    addItem(item: any): void {
        this.dataStorage.set(this.dataStorage.size, item)
    }
}

const i = new iterator1()
i.addItem(123)
i.addItem(456)
i.addItem('dolphin')
while(i.hasNext()){
    console.log(i.next())
}
console.log(`====================`)
const i2 = new iterator2()
i2.addItem(123)
i2.addItem(456)
i2.addItem('dolphin')
while(i2.hasNext()){
    console.log(i2.next())
}