Typescript学习总结之类

1. 类的定义和使用

class Student {
    name;

    say() { 
        console.log(this.name + " saying");
    }
}

var s1 = new Student();
s1.name = "zhangsan";
s1.say();

var s2 = new Student();
s2.name = "lisi";
s2.say();

　　

2. 类的构造函数

class Student {

    constructor(name: string) { 
        this.name = name;
    }

    name;

    say() { 
        console.log(this.name + " saying");
    }
}

var s1 = new Student("zhangsan");
s1.say();

var s2 = new Student("lisi");
s2.say();

　类的构造函数定义在constructor

效果图

上面的代码可以简写为

class Student {

    constructor(public name: string) { 
    }

    say() { 
        console.log(this.name + " saying");
    }
}

var s1 = new Student("zhangsan");
s1.say();

var s2 = new Student("lisi");
s2.say();

　　输出结果是一样的

3. 类的继承

class Student {

    constructor(public name: string) { 
    }

    say() { 
        console.log(this.name + " saying");
    }
}

class HighSchoolStudent extends Student { 

    constructor(name: string, no: string) {
        super(name)
     }
    no:string;
    study() {
        super.say();
     }
}

var hStudent = new HighSchoolStudent("wangwu","06169020");
hStudent.say();

　　

extends 代表要继承的类

super(name)调用父类的构造函数

super.say(); 调用父类的方法