1.4.2.1 参数问题

const sum = (num1,num2) => {
    return num1 + num2 
}

const power = num => {
  return num * num
}

1.4.2.2 函数内部

const test = () =>{
  console.log("hello zzz")
  console.log("hello vue")
}

// const mul = (num1,num2) => {
//   return num1 * num2
// }
const mul = (num1,num2) => num1* num2
// const log = () => {
//   console.log("log")
// }
const log = () => console.log("log")