Programming Forums > Web Development and Design > JavaScript and Client-Side Browser Scripting

Smessed-Up · Mar 7th, 2008, 4:53 AM

basically once one of the images is created randomly i want it removed from the array so it cant come up again but for some reason not all the images are appearing anyway heres what ive got whats wrong/missing?

[code]var image=new Array();
var g='.gif';
image[0]='image1'+g;
image[1]='image2'+g;
image[2]='image3'+g;
image[3]='image4'+g;
image[4]='image5'+g;
var l=image.length;
var buff=new Array();
for(i=0;i<l;i++){

buff[i]=new Image();
buff[i].src=image[i];

}

var randomNumber=Math.floor(Math.random()*l);
for(i=0;i<l;i++){

document.write('<img src="'+image[randomNumber]+'">');
image.splice(randomNumber,1);

}

grimpirate · Mar 7th, 2008, 5:38 PM

If you want to display all 5 images it's easier just to do the following:

(Toggle Plain Text)

<script type="text/javascript">
<!--
	for(var i = 0; i < 5; i++) {
		document.write('<img src="image"' + (i + 1) + '.gif">');
	}
//-->
</script>

Also be sure to properly enclose your code in code tags.

grimpirate · Mar 7th, 2008, 5:59 PM

If you want them to appear in a random order, for whatever reason:

(Toggle Plain Text)

<script type="text/javascript">
<!--
	var imgCount = 5;
	var image = new Array();
	for(var i = 0; i < imgCount; i++) {
		image.push('image' + (i + 1) + '.gif');
	}
	while(image.length > 0){
		var randomIndex = Math.floor(Math.random() * image.length);
		document.write('<img src="' + image[randomIndex] + '" alt="' + image[randomIndex] + '">');
		image.splice(randomIndex, 1);
	}
//-->
</script>

The issue with your code is that when you splice the array you're not taking into account the fact that the array size is changing dynamically. Therefore, you're generating non-existent indices. Whenever you splice an array you're going to be shortening its length, and the result will have new indices. Thus, when you have 5 elements your random number generation needs to be from 0 to 4, when you remove one and have 4 elements it needs to be from 0 to 3, and so on, until you have no more elements left in the array.

Smessed-Up · Mar 7th, 2008, 7:40 PM

Ah i see now thankyou for your help.

Mar 7th, 2008, 4:53 AM	#1
Smessed-Up Newbie Join Date: Mar 2008 Posts: 2 Rep Power: 0	Random image array basically once one of the images is created randomly i want it removed from the array so it cant come up again but for some reason not all the images are appearing anyway heres what ive got whats wrong/missing? [code]var image=new Array(); var g='.gif'; image[0]='image1'+g; image[1]='image2'+g; image[2]='image3'+g; image[3]='image4'+g; image[4]='image5'+g; var l=image.length; var buff=new Array(); for(i=0;i<l;i++){ buff[i]=new Image(); buff[i].src=image[i]; } var randomNumber=Math.floor(Math.random()*l); for(i=0;i<l;i++){ document.write('<img src="'+image[randomNumber]+'">'); image.splice(randomNumber,1); }

Mar 7th, 2008, 5:38 PM	#2
grimpirate King of Portal Join Date: Sep 2005 Posts: 369 Rep Power: 3	Re: Random image array If you want to display all 5 images it's easier just to do the following: (Toggle Plain Text) <script type="text/javascript"> <!-- for(var i = 0; i < 5; i++) { document.write('<img src="image"' + (i + 1) + '.gif">'); } //--> </script> <script type="text/javascript"> <!-- for(var i = 0; i < 5; i++) { document.write('<img src="image"' + (i + 1) + '.gif">'); } //--> </script> Also be sure to properly enclose your code in code tags. __________________ You are here to serve the board. So post well... and live. SPAMMING SPEED! GrimBB \| Mimesis

Mar 7th, 2008, 5:59 PM	#3
grimpirate King of Portal Join Date: Sep 2005 Posts: 369 Rep Power: 3	Re: Random image array If you want them to appear in a random order, for whatever reason: (Toggle Plain Text) <script type="text/javascript"> <!-- var imgCount = 5; var image = new Array(); for(var i = 0; i < imgCount; i++) { image.push('image' + (i + 1) + '.gif'); } while(image.length > 0){ var randomIndex = Math.floor(Math.random() * image.length); document.write('<img src="' + image[randomIndex] + '" alt="' + image[randomIndex] + '">'); image.splice(randomIndex, 1); } //--> </script> <script type="text/javascript"> <!-- var imgCount = 5; var image = new Array(); for(var i = 0; i < imgCount; i++) { image.push('image' + (i + 1) + '.gif'); } while(image.length > 0){ var randomIndex = Math.floor(Math.random() * image.length); document.write('<img src="' + image[randomIndex] + '" alt="' + image[randomIndex] + '">'); image.splice(randomIndex, 1); } //--> </script> The issue with your code is that when you splice the array you're not taking into account the fact that the array size is changing dynamically. Therefore, you're generating non-existent indices. Whenever you splice an array you're going to be shortening its length, and the result will have new indices. Thus, when you have 5 elements your random number generation needs to be from 0 to 4, when you remove one and have 4 elements it needs to be from 0 to 3, and so on, until you have no more elements left in the array. __________________ You are here to serve the board. So post well... and live. SPAMMING SPEED! GrimBB \| Mimesis

Mar 7th, 2008, 7:40 PM	#4
Smessed-Up Newbie Join Date: Mar 2008 Posts: 2 Rep Power: 0	Re: Random image array Ah i see now thankyou for your help.

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Programming Forums > Web Development and Design > JavaScript and Client-Side Browser Scripting

Random image array