How to delete from an array javascript?

Question

My code below opens a random website from the array but to stop going on the same website is there a way to delete it once it has been visited. Heres my attempt.

<button onclick="randomLink()";>Click here to go somewhere else!</button>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
<script type="text/javascript">
var randomLink = function () {
 var links = new Array(); 
 links[1] = "http://google.com";
 links[2]="http://bing.com";
 var max = (links.length)
 var randomNumber = Math.floor(Math.random()*max);
 var link = links[randomNumber];
 links.splice(randomNumber,1);
 $('iframe').attr('src', link);
}
</script>
<iframe src="" name="iframe_a" ></iframe>

• Mike Cluck: Define links outside of the function. You're deleting an item using splice but then putting it back when you run the function again.
• Marcos Pérez Gude: In addition to @MikeC, as a suggestion, don't define arrays with keys. You are missing the links[0] key and you can have problems. It's better if you don't define the key, it will be asigned automatically by javascript
• juvian: Math.floor(Math.random()*max) Can give 2 and will work incorrectly

Answer 1

Move links outside of the function:

var links = [
 "http://google.com",
 "http://bing.com"
];
var randomLink = function() {
 var max = links.length;
 var randomNumber = Math.floor(Math.random() * max);
 var link = links[randomNumber];
 links.splice(randomNumber, 1);
 $('iframe').attr('src', link);
};

• juvian: I think it´s Math.random() * (max-1). You could also just do var link = links.splice(Math.random() * (links.length-1), 1) and remove 4 lines

Answer 2

Every time you call the function, all url's are added to the array. Try to define the array outside the function. To delete something call splice!

best, Sebi

Answer 3

This is true code, you have ; after "".

<button onclick="randomLink()">Click here to go somewhere else!</button>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.0/jquery.min.js"></script>
<script type="text/javascript">
var randomLink = function () {
 var links = new Array(); 
 links[1] = "http://google.com";
 links[2]="http://bing.com";
 var max = (links.length)
 var randomNumber = Math.floor(Math.random()*max);
 var link = links[randomNumber];
 links.splice(randomNumber,1);
 $('iframe').attr('src', link);
}
</script>
<iframe src="" name="iframe_a" ></iframe>

• Mike Cluck: That's a minor typo, not the problem.

Answer 4

You do it using splice for example we have arr :

arr = [1,2,3,4,5,6]

To remove arr[2] which hold the value of 3 we can do :

arr.splice(2,1);

arr will become [1,2,4,5,6]

3 is the previous index of the deleted value and 1 is how many values to delete after that index .

You can read more about splice in MDN .