简单的Array实现

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简单的 Array 实现

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class Array {
  constructor(size = 10) {
    this.arr = [] // 数组
    this.size = size // 最大长度
    this.elems = 0 // 成员数量
  }

  add(elem) {
    if (this.arr.length == this.size) {
      console.log("Array is full")
      return
    }
    this.arr[this.elems++] = elem
    return true
  }

  find(elem) {
    for (let i = 0, len = this.elems; i < len; i++) {
      if (this.arr[i] == elem) return i
    }
    return -1
  }

  delete(elem) {
    let index = this.find(elem)
    if (index == -1) {
      console.log("Element not found")
      return
    }
    for (let i = index, len = this.elems - 1; i < len; i++)
      this.arr[i] = this.arr[i + 1]
    this.elems--
    return true
  }

  update(oldVal, newVal) {
    // only use for unique element
    let index = this.find(oldVal)
    if (index == -1) {
      console.log("Element not found")
      return
    }
    this.arr[index] = newVal
    return true
  }

  display() {
    let srt = ""
    for (let i = 0, len = this.elems; i < len; i++) {
      srt += "" + this.arr[i] + " "
    }
    console.log(srt)
  }

  length() {
    return this.elems
  }
}
var arr = new Array()
arr.add(1)
arr.add(2)
arr.add(3)
arr.add(4)
arr.display()
console.log(arr.length())

结果

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