can't convert undefined to object in javascript

Question

Update: I have added the fiddle. Please refer here. use web console for error.

I am writing a code for traveling salesman problem. Here is the code :

var ind =[];      //values selected 
var cp =[];
var X;
var Y;
var tour = [];


// no values selected in the starting
for(j=0;j<friends_cnt;j++) {
  ind[j] = 0;
}


// distances at i,i infinity
for(i=0;i<friends_cnt;i++) {
  distance[i][i] = 9999999999999;
}

var k = 0;
var X = 0;

tour[k] =  X;
ind[X] = 1;


var i =1;
while(i<friends_cnt &&  ind[i] === 0) {
  var min = 9999999999999;

    // finding minimum of the undeleted values
    for(j=0;j<friends_cnt;j++) {
      if(ind[j] === 0) {
        if(distance[X][j] < min) {
          min = distance[X][j];
          Y = j;  // y is the min city
        }
      }
    }


    k = k+1;               // counter for the starting city
    tour[k] = Y;           //city added
    ind[Y] = 1;            

   X = Y;
   i++;
}

k = k+1;
tour[k] = tour[1];

for(var q=0;q<k+1;q++) {
  console.log(tour[q]);
}

});
});

now here whenever i run my program, it shows an error

TypeError: can't convert undefined to object

in the line

var min = 9999999999999;

My question is that is this because JavaScript cant handle large numbers or something else ?

score 1 · Answer 1 · edited May 23 '17 at 10:26

1

Javascript's max number is 1.7976931348623157e+308 (aka the var Number.MAX_VALUE), so that shouldn't be an issue.

If you are trying to access an object of an object, it won't work.

You have distance[X][j]. That tries to access key j of distance[X]. To fix this, define distance[X] as an object:

distance[X] = [];

Other example:

var distance = [];

distance[i]
//undefined;

distance[i][i]
//syntax error

distance[i] = [];

distance[i][i]
//undefined;

For 2D arrays, see this question.

edited May 23 '17 at 10:26

Community

1
1

answered Feb 07 '13 at 05:11

hexacyanide

88,222
31
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162

Rest of the code runs fine. The problem comes when i try to play with the data ie distance[][]. – user1263375 Feb 07 '13 at 05:17
Added to answer - it's outlined in another question. Also, min and max Javascript integers are respectively `Number.MIN_VALUE` and `Number.MAX_VALUE`. – hexacyanide Feb 07 '13 at 05:29

asifsid88 · Answer 2 · 2013-02-07T07:09:28.587

0

Try this for minimum number var min = int.MinValue
For max number var max = int.MaxValue

Edited
Refer Reference

Number.Max_Value  
Number.Min_Value

UPDATED
If you see your code you have filled the ind[] from 0

for(j=0;j<friends_cnt;j++) {
  ind[j] = 0;
}

and in your while condition you have set value of i from 1. So for the last element it may be throwing error

edited Feb 07 '13 at 07:09

answered Feb 07 '13 at 05:10

asifsid88

4,631
20
30

will it add minimum value to variable min or a large number. I want large number – user1263375 Feb 07 '13 at 05:16
it says int is not defined. – user1263375 Feb 07 '13 at 05:23
`var min = 9999999999999;` works fine and is not the cause of the problem. – Ja͢ck Feb 07 '13 at 07:06

score 0 · Answer 3 · answered Feb 07 '13 at 07:05

The problem is actually here:

distance[i][i] = 9999999999999;

If distance is undefined or an empty array, that statement will fail. This should fix it:

var distance = []; // <-- this is missing from the top of your code

// ...

if (!distance[i]) {
    distance[i] = [];
}
distance[i][i] = 9999999999999;

can't convert undefined to object in javascript

3 Answers3