Change values of a pair of javascript arrays

Question

I'm a begginer and I'm coding this to change values of a whole array. For instance, my aim is to change ºC to ºK. But this code doesn't seems to work. It gives an error message: "j is undefined". What's wrong with this code?

//Original Arrays

var I_t1=new Array();
var V_t1=new Array();

//Arrays de la tabla 1
var K_t1=new Array();
var P_t1=new Array();

function kelvin() {
    var i;

    var j = new Array();
    var k = new Array();

    var k;
    var j=V_t1.lenght;   

    var k=I_t1.lenght; // La k será igual a la longitud del array T

    for(i=0;i<j.length;i++){   
        K_t1[i]= (V_t1[i] * 200);
    }

    for(i=0;i<k.length;i++){      
        P_t1[i]= (I_t1[i] * 400);
    }
}

Until here, the code. So my question is:

-How do I modify this funcion to archieve its aim?

Several things: Think about indentation - it's almost impossible to read without it. Secondly, you're redeclaring k in the kelvin function a total of 3 times and j two times - why? Thirdly, I_t1.lenght should be I_t1.length. Fourthly, you're setting j and k to a NUMBER, yet you're trying to call .length on them and a number doesn't have a length. Skip out the .length part in the for statements. — h2ooooooo
– h2ooooooo, Commented Jun 12, 2013 at 8:25

Aadit M Shah · Accepted Answer · 2013-06-12 08:36:21Z

3

Look at your spelling - it's .length, not .lenght!

edited Jun 12, 2013 at 8:36

Aadit M Shah

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answered Jun 12, 2013 at 8:32

lukas.pukenis

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2 Comments

heptagono Over a year ago

Wow!! length... No more errors in the web browser console. Thanks a lot. EDIT: But still, it doesn't make any change in the values...

lukas.pukenis Over a year ago

I am really happy that helped you! If something is undefined always look for spelling first - you may have missed a letter or swapped some :)

Dhruv Chandna · Accepted Answer · 2013-06-12 08:40:18Z

2

As others mentioned there is a problem in the .length. But I would recommend a different approach to solve this problem. Try and use higher order functions like "map" to make this work. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map

e.g. A function to change ºC to ºK would be something like:

function celciusToKelvin(celciusVal){
   return celciusVal + 274.15;
}

Now if you have an array of celcius values like var celciusValues = [12,23,34,45];, you can call the map function like:

var kelvinValues = celciusValues.map(celciusToKelvin);

answered Jun 12, 2013 at 8:40

Dhruv Chandna

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2 Comments

heptagono Over a year ago

Hum, thanks! I'm going to try this solution changing the approach I've been following since now.

heptagono Over a year ago

Wait a moment, there is something odd here. I will answer my own question to show the results.

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