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>

Define `links` outside of the function. You're deleting an item using `splice` but then putting it back when you run the function again. — Mike Cluck, Feb 11 '16 at 17:30
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 — Marcos Pérez Gude, Feb 11 '16 at 17:31
`Math.floor(Math.random()*max)` Can give 2 and will work incorrectly — juvian, Feb 11 '16 at 17:31

score 1 · Accepted Answer · answered Feb 11 '16 at 17:31

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);
};

answered Feb 11 '16 at 17:31

Mike Cluck

28,921
12
72
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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 – juvian Feb 11 '16 at 17:35

score 0 · Answer 2 · answered Feb 11 '16 at 17:32

0

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

answered Feb 11 '16 at 17:32

sebi0920

293
2
10

score 0 · Answer 3 · answered Feb 11 '16 at 17:33

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>

That's a minor typo, not the problem. – Mike Cluck Feb 11 '16 at 17:34 — Mike Cluck, Feb 11 '16 at 17:34

score 0 · Answer 4 · answered Feb 11 '16 at 17:34

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 .

How to delete from an array javascript?

4 Answers4