javascript - 我如何在子 javascript 代码中使用父变量？

Question

此代码在子级中使用继承 我在场景中添加了一些在父级中声明的东西 我该怎么做 它在子级中看到场景时出错

 function parent    (domElement, renderStatistics) {
    this.scene = new THREE.Scene();
    }
function child(domElement) {
    parent.call(this, domElement);
    this.init();
}
child.prototype = Object.create(parent.prototype);

child.prototype.constructor = Young;


child.prototype.init = function () {
function createLab(geometry) {
        var mesh = new THREE.Mesh(geometry, new THREE.MeshFaceMaterial());
        this.scene.add(mesh);  // this error Cannot call method 'add' of undefined
    }
}

Answer 1

child.prototype.init = function () {
var _this = this;
    function createLab(geometry) {
        var mesh = new THREE.Mesh(geometry, new THREE.MeshFaceMaterial());
        _this.scene.add(mesh);  
    }
}