實(shí)現(xiàn)一個(gè)字符串模板函數(shù)

const a = {
  b: 'xxx',
  c: ['a', 'b'],
  d: {
   a: 'a'
  }
}

const string = 'aaa${a.b}bbb${a.c[0]}ccc${a.d.a}'
transform(string, a) => 'aaaxxxbbbaccca'

解題思路

通過正則表達(dá)式將插值部分匹配出來替換成對(duì)象屬性值

const a = {
  b: 'xxx',
  c: ['a', 'b'],
  d: {
    a: 'a'
  }
}
const transform = (str) => {
  let newStr = str.replace(/\$\{.*?\}/g, (res) => {//正則表達(dá)式匹配${xxxx}
    let newValue = ""
    try {
      newValue = eval(res.slice(2, -1));//截取插值部分
    }
    catch (exception) {//如果取值報(bào)錯(cuò)將匹配的字符串部分原樣返回
      newValue = res;
    }
    return newValue;
  })
  return newStr;
}
const str = 'aaa${a.b}bbb${a.c[0]}ccc${a.d.a}';
console.log(transform(str));//aaaxxxbbbaccca