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: 402 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. __________________ Lo, there do I see my father. 'Lo, there do I see My mother, and my sisters, and my brothers. 'Lo, there do I see The line of my people... Back to the beginning. 'Lo, they do call to me. They bid me take my place among them. In the halls of Valhalla... Where the brave... May live... ...forever.. GrimBB \| Mimesis

Mar 7th, 2008, 5:59 PM	#3
grimpirate King of Portal Join Date: Sep 2005 Posts: 402 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. __________________ Lo, there do I see my father. 'Lo, there do I see My mother, and my sisters, and my brothers. 'Lo, there do I see The line of my people... Back to the beginning. 'Lo, they do call to me. They bid me take my place among them. In the halls of Valhalla... Where the brave... May live... ...forever.. 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