说说你对深浅拷贝的理解？并实现一个对数组和对象深拷贝的方法

Answer 1

function deepClone(val) {
  function getType(_val) {
    return Object.prototype.toString.call(_val).replace(/[\[\s\]]|(object)/g, '')
  }
  const valType = getType(val);
  if (valType !== 'Object' && valType !== 'Array') return val
  let output = {}
  if (valType === 'Array') {
    output = []
    val.forEach(v => {
      const curValType = getType(v)
      if (curValType === 'Array' || curValType === 'Object') {
        output.push(deepClone(v))
      } else {
        output.push(v)
      }
    })
  } else if (valType === 'Object') {
    Object.keys(val).forEach(v => {
      const curValType = getType(v)
      if (curValType === 'Array' || curValType === 'Object') {
        output[v]= (deepClone(val[v]))
      } else {
        output[v]= (val[v])
      }
    })
  }
  return output
}

const obj = {
  a: 1,
  b: [
    {
      b1: 'b1',
      b2: {
        b2_1: 'b2_1'
      }
    }
  ]
}

const clone = deepClone(obj)

obj.b = { b: 'b' }

console.log(clone)
console.log(obj)