[RESOLVED] Array Loop problem

[kunjald]

Hi,

I am recently working with an application. Where I need 4 unique values from an array in such a way that it should checking random item every time.

For eg:-

Main_Array = ["one","two","three","four","five","six","seven "];

Sub_Array = ["three"]; // initially it holds one value

for(each value of Sub_Array)
{
if(Sub_Array[value] == Main_Array[RandomNumber])
{
// It should get another random item from Main_Arr and check
}
else
{
Sub_Array.push(Main_Array[RandomNumber]);
//next time updated Sub_Arrays values should be checked.
}
}


// I want an array with 3 unique values other then the one already pushed in
Sub_Array

I am trying but I don't get unique values, or something gets wrong which I am not able to solve. Looking forward desperately for some help

[5TonsOfFlax]

Do you need Main_Array to remain unchanged? It doesn't matter much, just determines whether we need to clone it. I'll assume you do. Why put "three" in Main_Array if it's not eligible to be selected?

/**
* @param n int number of values to select from arr.
* @param arr Array from which to select values
* @return a new Array containing n values.
**/
function selectUniqueValuesFrom(n:int, arr:Array, forbiddenValues:Array):Array{
  if (n > arr.length){
     //throw some error or return null or something.
  }
  var arrClone:Array = arr.filter(notIn(forbiddenValues));
  
  var toreturn:Array = [];
  for (var i:int = 0; i < n; i++){
    var k:int = Math.floor(Math.random()*arrClone.length);
    var elem:* = arrClone[k];
    toreturn.push(elem);
    arrClone.splice(k, 1);
  }
  return toreturn;
}


/**
* Builds a FUNCTION to use as a callback to filter
* @param values Array of values to exclude via filter
* @return Function
*/
function notIn(values:Array):Function{
  return function(item:*, index:int, array:Array):Boolean{
    return values.indexOf(item) == -1;
  }
}

Sub_Array = ["three"].concat(selectUniqueValuesFrom(4, Main_Array, ["three"]));

I got a little fancy with the filter use, but it should work. There are other ways too. The most complicating part was that you want to pre-fill it partially.

[kunjald]

Thanks a lot your code works well. Actually I am making one application where I have exam module. So I coded the correct answer and I push that initially in Sub_array, so I want the rest 3 wrong options from the whole array but unique.

I just thought that this would be possible way to do this. There are other ways even. But really thankful for help