How to call a function from the constructor of the JS class

Question

I am creating a matrix class (which will be used in the reaction application), which I would like to define as follows:

class Matrix extends Object {
    constructor(r, c) {
        super();
        this.rows = new Array(r);
        for (var i=0; i<r; i++) {
            this.rows[i] = new Array(c);
        }
        this.assign((v,i,j) => (i===j)? 1:0);   // ERROR HERE
    }
    assign(f) {
        for (var i=0; i<this.rows.length; i++) {
            for (var j=0; j<this.rows[i].length; j++) {
                this.rows[i][j] = f(this.rows[i][j], i, j);
            }
        }
    }
    // and so on

This compiles through webpack, but when I work, I get an error on the Chrome console saying that _this.assign is not a function .

I can get it to work as follows:

constructor(r, c) {
    super();
    this.rows = new Array(r);
    for (var i=0; i<r; i++) {
        this.rows[i] = new Array(c);
    }
    this.assign = function(f) {
        for (var i=0; i<r; i++) {
            for (var j=0; j<r; j++) {
                this.rows[i][j] = f(this.rows[i][j], i, j);
            }
        }
    };
    this.assign((v,i,j) => (i===j)? 1:0);
}

But this is wrong, right? I would not need to define all the functions of the object in the constructor, right? In the same file, I define reaction classes, for example:

class MatrixComponent extends React.Component { ... }

and they can call functions without defining them in the constructor. What am I missing?

Answer 1

extends Object super(), , .

class Matrix { // extends Object {
    constructor(r, c) {
        // super();
        this.assign();
    }
    assign() {
    }
}

, , Object. extends Object , .

---

, extends Object ​​Babel. Chromium , : https://bugs.chromium.org/p/v8/issues/detail?id=3886

, Babel transpiled es5 .

_possibleConstructorReturn super, Babel , . : " , (, assign)". Object , Javascript Object .

_possibleConstructorReturn(OtherClassExtender, OtherClass) , typeof call undefined, OtherClassExtender.

_possibleConstructorReturn(ObjectExtender, Object) typeof call is Object, Object.

assign. assign - Object, (new Object).assign, .

Answer 2

, null vs Object :

class Matrix extends null { ... }

, , , , , . , : , .