call与bind

输出是什么？

const person = { name: 'Lydia' }

function sayHi(age) {
  console.log(`${this.name} is ${age}`)
}

sayHi.call(person, 21)
sayHi.bind(person, 21)

选项

• A: undefined is 21 Lydia is 21

• B: function function

• C: Lydia is 21 Lydia is 21

• D: Lydia is 21 function

答案