如何从类中的另一个函数调用一个函数

Question

我有以下问题：我想printHello从函数调用函数testHello。该printHello函数可以独立工作，但是，当我尝试printHello从该testHello函数调用时，出现引用错误。谢谢您的帮助。

---

class Test {
  constructor(name) {
    this.name;
  }

  printHello(parameter) {
    console.log(parameter);
  }

  testHello() {
    printHello(printHello(this.name));
  }

}
var test = new Test("Sandro");
test.printHello("hello"); //works, prints "Hello" to the Console 
test.testHello(); // does not work: Reference Error: printHello is not defined

Answer 1

使用this关键字。另外，您有几个错误（我对它们进行了评论）

class Test{
    constructor(name){
        this.name = name; // <- you need to assign the `name` to `this.name`
    }

    printHello(parameter){
        console.log(parameter);
    }

    testHello(){
        this.printHello(this.name); // <- you had double invocation here
    }

}
var test = new Test("Sandro");
test.printHello("hello");   //works, prints "Hello" to the Console 
test.testHello();  // does not work: Reference Error: printHello is not defined