2021-09-07

````

let arr = [1, 2, 3, 4, 5]

let text = ''

for (let v of arr) {

  if (v === 3) {

    break

  }

  text += v + ','

}

console.log(text) // "1,2,"

````. 

使用some进行代码优化

````

let arr = [1, 2, 3, 4, 5]

let text = ''

arr.some(v => {

  if (v === 3) {

    return true

  }

  text += v + ','

})

console.log(text) // "1,2,"

````