CODEWITHSUNDEEP
javascriptarrays
Simbox97
Simbox97

Reputation: 113

Move values from one array to another and remove them

I have a 20 number array. Now I pick (randomly) 5 of these and i wanna put them into another empty array. How can I do? And also, how can I hide them from the first array when they're displayed? Thank you all.

var tenNumbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 20, 42, 178, 54, 76, 32, 12, 38, 154, 234];
var randomNumbers = document.getElementById("demo");
randomNumbers.innerHTML = tenNumbers[Math.floor(Math.random()*tenNumbers.length)];

Upvotes: 2

Views: 2676

Answers (4)

Fabjan
Fabjan

Reputation: 13676

function getRandomInt(min, max) {
    return Math.floor(Math.random() * (max - min + 1)) + min;
}

var tenNumbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 20, 42, 178, 54, 76, 32, 12, 38, 154, 234];

var randNums = [];

var randomNumbers = document.getElementById("demo");

for(var i = 0; i < 5; i++) 
{
   var index = getRandomInt(0, tenNumbers.length - 1);        
   randNums.push(tenNumbers[index]); 
   randomNumbers.innerHTML += tenNumbers[index] + ", ";
   tenNumbers.splice(index, 1);
}
<div id="demo">
</div>

Upvotes: 0

pawel
pawel

Reputation: 36965

You could also pick 5 random elements and move them to a new array using .sort & .splice one-liner:

var outArray = tenNumbers.sort(function(){ return Math.random() - 0.5; }).splice(0,5);

Upvotes: 0

Mouser
Mouser

Reputation: 13304

var tenNumbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 20, 42, 178, 54, 76, 32, 12, 38, 154, 234];

var randomNumbersArray = [];
for (var i = 0; i < 5; i++)
{
    randomNumbersArray.push(tenNumbers.splice(Math.floor(Math.random()*tenNumbers.length), 1));
}

document.getElementById("random").innerHTML = randomNumbersArray.join("<br />");
<div id="random"></div>

This should do it.

  • Run loop until second array has five entries.
  • delete entry from original array with splice to avoid doubles.

Upvotes: 2

CodingIntrigue
CodingIntrigue

Reputation: 78545

Seems like you should be able to use splice to remove a random element from the original array, then push that result onto a new array:

var tenNumbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 20, 42, 178, 54, 76, 32, 12, 38, 154, 234];
var outArray = [];
for(var i=0; i<5; i++) {
    outArray.push(tenNumbers.splice(Math.floor(Math.random()*tenNumbers.length), 1)[0]);
}
document.write(outArray + "<br />" + tenNumbers);

Upvotes: 4

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