Maximum call stack size exceeded - Infinite Loop

Question

I have the following JavaScript class:

class TrieNode
    {
        constructor()
        {
            switch(arguments.length)
            {
                case 0 : this.constructorNoParam();
                         break;
                case 1 : this.constructorOneParam(arguments[0]);
                         break;
            }
        }

        constructorOneParam(c)
        {
            this.children=new TrieNode();
            this.c = c;
            this.isLeaf;
        }

        constructorNoParam()
        {
            this.children = new TrieNode();
            this.c;
            this.isLeaf;
        }
    }

The reason why I am getting this error is that every time I am creating the children variable, the constructor creates another instance of the TrieNode class and results in an infinite loop.

Is there a way that I can create only ONE variable for the whole class? I had to put it in the constructor since in JavaScript classes, variables can only be created inside functions.

Basically, what I want to achieve would look like this in java:

public class TrieNode {

        public char c;
        TrieNode children = new TrieNode();
        public  boolean isLeaf;

        public TrieNode() {}

        public TrieNode(char c){
            this.c = c;
        }

Thanks

Possible duplicate of [Maximum call stack size exceeded error](http://stackoverflow.com/questions/6095530/maximum-call-stack-size-exceeded-error) — Marcos Pérez Gude, Nov 24 '16 at 10:59

Rajaprabhu Aravindasamy · Accepted Answer · 2016-11-24T13:25:49.097

1

You can create a static variable for this,

class TrieNode {
  constructor(time) {
      if(time === "1") return;
      switch(arguments.length) {
        case 0 : this.constructorNoParam();
        break;
        case 1 : this.constructorOneParam(arguments[0]);
        break;
      }
  }
  constructorOneParam(c) {
      this.children= TrieNode.children;
      this.c = c;
      this.isLeaf;
  }
  constructorNoParam() {
      this.children = TrieNode.children;
      this.c;
      this.isLeaf;
  }
}

TrieNode.children = new TrieNode("1");

// Now the code wont fall into a recursive loop
var x = new TrieNode();
var y = new TrieNode("foo", "bar");

And create a provision for the first time setup.

You can alternatively do that like below if you want new instance for children,

   class TrieNode {
      constructor(time) {
          if(time === "1") return;
          switch(arguments.length) {
            case 0 : this.constructorNoParam();
            break;
            case 1 : this.constructorOneParam(arguments[0]);
            break;
          }
      }
      constructorOneParam(c) {
          this.children= new TrieNode("1");
          this.c = c;
          this.isLeaf;
      }
      constructorNoParam() {
          this.children = new TrieNode("1");
          this.c;
          this.isLeaf;
      }
    }

edited Nov 24 '16 at 13:25

answered Nov 24 '16 at 11:03

Rajaprabhu Aravindasamy

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@Techs Can you differentiate the call for the first time setup? – Rajaprabhu Aravindasamy Nov 24 '16 at 11:12
I thought about it. But I can't think of a possible way how I can do that – Techs Nov 24 '16 at 11:16
Added an explanation of what I would like to achieve in Java – Techs Nov 24 '16 at 11:20
@Techs Haven't you seen the updated version of my answer? It would address your issue. – Rajaprabhu Aravindasamy Nov 24 '16 at 11:21
1

Sorry didn't notice that! Yes it's working :) Thanks – Techs Nov 24 '16 at 11:28
With further debugging, I am noticing that the value of `this.children` is now being the same for all the children elements. Is there a way to prevent this? Sorry, still new to JavaScript – Techs Nov 24 '16 at 13:00
@Techs You have asked this. _Is there a way that I can create only ONE variable for the whole class?_ – Rajaprabhu Aravindasamy Nov 24 '16 at 13:16
Sorry for that. I will not edit the question since your reply was an answer to what I've asked. Is there a way I can create a `children` variable for each `TrieNode` class, without having this error ? – Techs Nov 24 '16 at 13:20
@Techs See the updated answer. We don't require a static variable. – Rajaprabhu Aravindasamy Nov 24 '16 at 13:21
I think there is a typo - `this.children = new TrieNode("1");` - It should be like this right? – Techs Nov 24 '16 at 13:24
@Techs Oops. My bad. Yeah that was a typo. – Rajaprabhu Aravindasamy Nov 24 '16 at 13:25

Maximum call stack size exceeded - Infinite Loop

1 Answers1