技術標籤：vuejs

！！可以將表示式轉換成布林型別

let i = 1
console.log(!!i)
// true

+可以把陣列字串型別轉換成number型別

let data = ['12', '23', '34']
let list = data.map(item => +item)
console.log(data) // ['12', '23', '34']
console.log(list) // [12, 23, 34]

判斷字串中某個字元出現的個數

var s='j1111hdoi11we12es11dds';
var n=(s.split('1')).length-
 
1;
console.log(n); // 9

物件變陣列

let u ={
	"0": 'ww',
	"1": 'u',
	length: 2
}
console.log(Array.from(u)) // ['ww', 'u']

let year = 2019

let y = Array.from({ length: 3 }, (val, index) => {
        if (index === 0) {
          return {
            title: '請選擇',
            value: 0,
            disabled:
 
 true
          }
        }
        return {
          title: year + index,
          value: year + index
        }
      })
console.log(y)

…運算子

合併物件

let y ={
	name: 'ui'
}
let a = {
	value: 1
}
let u = {
	...y,
	...a,
	...{
		age: 89
	}
}
console.log(u) // {age: 89,name: "ui",value: 1}

合併陣列

let list = [1,2,3]
let list2 = [4,5,6]
console.log([...list, ...list2]) // [1,2,3,4,5,6]

陣列轉換成三個一行顯示

getSourceData (obj) {
  var result = []
  for (var i = 0, len = obj.length; i < len; i += 3) {
    result.push(obj.slice(i, i + 3))
  }
  return result
},