2つのオブジェクト、1つは「関数ではない」

Question

コードの最後に、.getChildren関数を定義したノードのインスタンスを2つ作成しますが、Uncaught TypeError: t2.getChildren is not a functionが得られます。また、なぜt2ではなくt1でこれを言っているのですか？

function Node(value) { 

    // based on graph theory, we give 
    this.value = value; 
    this.children = []; 
    this.parent = null; 

    // set and get functions 
    this.setParent = function(node) { 
     this.parent = node; 
    }; 

    this.getParent = function() { 
     return this.parent; 
    }; 

    this.addChild = function(node) { 
     node.setParent(this); 
      this.children[this.children.length] = node; 
    }; 

    this.getChildren = function() { 
     return this.children; 
    }; 

} 


// check Identical 

var subTreeFinder = function (t1,t2) { 

    // base cases 

    if (t2==null) { 
    return true; // empty trees are subtrees to all trees 
    } 

    if (t1==null){ 
    return false; // a non-empty tree can't fit in an empty tree 
    } 

    if (checkIdentical(t1,t2)) { 
    return true; 
    } 

    var t1Children = t1.getChildren(); 
    var t2Children = t2.getChildren(); 

    return subTreeFinder(t1Children.every(subTreeFinder) || t2Children.every(subTreeFinder)); 
} 


// check Identical 
    var checkIdentical = function (t1,t2) { 

     // base case 
     if (t1==null && t2 == null) { 
     return true; 
     } 


     if (t1 != null && t2 != null) { 

     var t1Children = t1.getChildren(); 
     var t2Children = t2.getChildren(); 

     // an obvious case and time saver 
     if (t1Children.length != t2Children.length){ 
      return false; 
     } 

     // recursive call. for every arr. element in both sets of kids check if we recurrsively get back true 
     if (t1.value == t2.value && t1Children.every(checkIdentical) && t2Children.every(checkIdentical)) { 
      return true; 
     } 

     } 

     // here: either one is null and the other ins't, so false. 
     return false; 

    } 

// The actual Trees 

var dom = new Node('a'); // root 
dom.addChild(new Node('b')); 
dom.addChild(new Node('c')); 

var vdom = new Node('x'); // root 
vdom.addChild(new Node('y')); 
vdom.addChild(new Node('z')); 

console.log(subTreeFinder(dom, vdom)); 

// console.log(dom); // Should read entire Demo Tree object (unfold to see contents) 

Answer 1

コードにArray.prototype.everyの実装が間違っています。 ここに右の構文をチェックしてください：https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/every

を下に見つけてください：それはcheckIdentical`が何をしているか `subTreeFinder`と `かなり不明だコード

function Node(value) { 

    // based on graph theory, we give 
    this.value = value; 
    this.children = []; 
    this.parent = null; 

    // set and get functions 
    this.setParent = function(node) { 
     this.parent = node; 
    }; 

    this.getParent = function() { 
     return this.parent; 
    }; 

    this.addChild = function(node) { 
     node.setParent(this); 
      this.children[this.children.length] = node; 
    }; 

    this.getChildren = function() { 
     return this.children; 
    }; 

} 


// check Identical 

var subTreeFinder = function (t1,t2) { 
console.error(t1, t2) 
    // base cases 

    if (t2==null) { 
    return true; // empty trees are subtrees to all trees 
    } 

    if (t1==null){ 
    return false; // a non-empty tree can't fit in an empty tree 
    } 

    if (checkIdentical(t1,t2)) { 
    return true; 
    } 
debugger; 
    var t1Children = t1.getChildren(); 
    var t2Children = t2.getChildren(); 

    return subTreeFinder(t1Children.every(function(element) {subTreeFinder(element)}) || t2Children.every(function(element) {subTreeFinder(element)})); 
} 


// check Identical 
    var checkIdentical = function (t1,t2) { 

     // base case 
     if (t1==null && t2 == null) { 
     return true; 
     } 


     if (t1 != null && t2 != null) { 

     var t1Children = t1.getChildren(); 
     var t2Children = t2.getChildren(); 

     // an obvious case and time saver 
     if (t1Children.length != t2Children.length){ 
      return false; 
     } 

     // recursive call. for every arr. element in both sets of kids check if we recurrsively get back true 
     if (t1.value == t2.value && t1Children.every(checkIdentical) && t2Children.every(checkIdentical)) { 
      return true; 
     } 

     } 

     // here: either one is null and the other ins't, so false. 
     return false; 

    } 

// The actual Trees 

var dom = new Node('a'); // root 
dom.addChild(new Node('b')); 
dom.addChild(new Node('c')); 

var vdom = new Node('x'); // root 
vdom.addChild(new Node('y')); 
vdom.addChild(new Node('z')); 

console.log(subTreeFinder(dom, vdom)); 

Answer 2

あなたは、コールバックが最初のパラメータとして、実際のアイテムを持っており、実際のアイテムのインデックスPARAMTER秒としてArray#everyのAPIを、欠場。

インデックスはNodeのインスタンスではありません。したがって、方法getChildrenは利用できません。