Problem with variable

[pkng]

Hi!

function BytBild2(number) {
test = "bild" + number.toString();

document.getElementById("storbild").src="bilder/bilder_stora/" + test + ".jpg";

This dosen't work! But if I write bild2, then it works! How come it dosen't work and what do I do wrong? What I'm trying to do is to concatenating different parts to a variable. bild2 ha a value from the beginning. And I just wanted to save a lot of code to put bild + number and use just one line of code instead of several?!

Appreciate som help! Thanks!

[Declan1991]

How do you call it?

And there is no need to call toString. This will do.

function BytBild2(number) {
test = "bild" + number;
document.getElementById("storbild").src="bilder/bilder_stora/" + test + ".jpg";
}
BytBild2(2);

[pkng]

Thanks! But are you sure it works? I have tried this several times! I'm unsure if it's possible to create a new variable named 'test' by concatenating bild + 1 which already is a variable name, 'bild1', with a value of 0011_1. I can't get this value to the new variable 'test'!?

I call it like BytBild2(2); but as I wrote variables 'bild1' to 'bild5' are already declared variables with different values before I call BytBild2(2);
My thought was to just use less amount of lines of code and create a new variable instead of

if (number == 1) {
document.getElementById("storbild").src="bilder/bilder_stora/" +bild1+ ".jpg";} bild1 could have the value of 0004_2

......

if (number == 5) {
document.getElementById("storbild").src="bilder/bilder_stora/" +bild5+ ".jpg";} bild5 could have the value of 0015_5


What I wanted was just this few lines:

function BytBild2(3) {
test = ???? + number
document.getElementById("storbild").src="bilder/bilder_stora/" + test + ".jpg";
}

Do you understand how I mean?

[Vince616]

Hi bud

I think your problem is that you forgot to declare your "test" variable

   test = "bild"+ number

should be

   var test = "bild"+ number

That said, if it were me I wouldnt bother with the "test" variable

  function ByBild2(number){
    document.getElementById("storbild").src="bilder/bilder_stora/bild" + number + ".jpg"; 
                        }

V

[pkng]

Hi!

It's not necessary to declare a variable in java script. And if you declare the variable inside a function it gets local scope and will not be global!

I'm trying to create a string, I'm trying to create a new variable and assign a value to it, but guess it's impossible!?

[Fang]

var test = window["bild" + number];

[pkng]

Sorry, but it doesn't work!

var number = 2;
var test = window["bild_" + number];

if I also add an Alert I get a message saying 'undefined' and after some time. Seems like browser locks!?

?

[Declan1991]

I know for absolute sure, guaranteed, that this will do what I say it does.

function function BytBild2(number) {
alert("bilder/bilder_stora/bild" + number + ".jpg");
}
BytBild2(2);

That code will alert "bilder/bilder_stora/bild2.jpg". If not, you have problems elsewhere in your code. Guaranteed.

[Fang]

which already is a variable name, 'bild1', with a value of 0011_1. I can't get this value to the new variable 'test'!?

Like this?

function BytBild2(number) {
var test = window["bild" + number];
document.getElementById("storbild").src="bilder/bilder_stora/" + test + ".jpg";
}
var bild1 = '0011_1';
BytBild2(1);

[SparoHawk]

Guys, what he wants is to create a variable name from string to read its value. Something by the like of the following in PHP:

<?php
    $blid1 ='test'; 
    $num = 1;
    $test = ${'blid'.$num};
    
    echo $test;
?>

Edit:
Fang's proposal is a nice work around. Try that.