JavaScript halt pushing when a distinct value is encountered

Question

JavaScript halt pushing when a distinct value is encountered

In this coding challenge, I am attempting to populate a 2D array using a while loop. However, I want the loop to stop pushing values into the array when the first column contains three different unique values.

The initial code looks like this:

var maxunique;
var i = 0;

while (countunique(arr) != maxunique) {

    // code that adds data to the array
    arr[i].push(RandomNumber(1,8));
    arr[i].push(i+1);
i++;
}


function countunique(arr)
{
    // function implementation here
}

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

This code currently returns the following array:

arr:  [ [ 4, 1 ],
  [ 7, 2 ],
  [ 5, 3 ],
  [ 5, 4 ],
  [ 3, 5 ],
  [ 1, 6 ],
  [ 7, 7 ],
  [ 8, 8 ],
  [ 5, 9 ],
  [ 5, 10 ] ]

The desired result should be:

arr:  [ [ 4, 1 ],
  [ 7, 2 ],
  [ 5, 3 ] ]

In this case, the process stops after the third pair is added to the array, as it already contains three unique values in the first column.

I am unsure of how to modify the code to achieve this and whether a while or for loop would be more appropriate. Any suggestions?

javascript arrays count 2d unique

Answer 1

Answer №1

Within the iteration process used to populate the 2D array, implement a mechanism that directs the array to a validation function ensuring the presence of three unique elements as the initial components within each individual sub-array. Below is the snippet containing the validation function which evaluates and returns true until it detects the existence of three distinct elements, upon which it returns false.

var a = []; //; 
var i = 0;
while (check(a)) {
  a[i]=[];
  a[i].push(RandomNumber(1, 42));
  a[i].push(i + 1);
  i++;
}

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

function check(arr) {
  var length = arr.length;
  var tmp = [];
  for (var j = 0; j < length; j++) {
    if (tmp.indexOf(arr[j][0]) === -1) {
      tmp.push(arr[j][0]);
    }
    if (tmp.length === 3) {
      return false;
    }
  }
  return true;
}
console.log('test: ', a);
console.log('check: ', check(a));

Answer 2

Within the iteration process used to populate the 2D array, implement a mechanism that directs the array to a validation function ensuring the presence of three unique elements as the initial components within each individual sub-array. Below is the snippet containing the validation function which evaluates and returns true until it detects the existence of three distinct elements, upon which it returns false.

var a = []; //; 
var i = 0;
while (check(a)) {
  a[i]=[];
  a[i].push(RandomNumber(1, 42));
  a[i].push(i + 1);
  i++;
}

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

function check(arr) {
  var length = arr.length;
  var tmp = [];
  for (var j = 0; j < length; j++) {
    if (tmp.indexOf(arr[j][0]) === -1) {
      tmp.push(arr[j][0]);
    }
    if (tmp.length === 3) {
      return false;
    }
  }
  return true;
}
console.log('test: ', a);
console.log('check: ', check(a));

Answer 3

Answer №2

To efficiently store and check the occurrence of each first number, you can utilize an object in JavaScript. In each iteration of a while loop, generate a random number for the first number and store it as a property in an object. Check if any value in this object equals 3 to break out of the loop.

var ar = [];
var obj = {}

while (true) {
  var firstNum = parseInt(Math.random() * 5) + 1;

  ar.push([firstNum, 1]);
  obj[firstNum] = (obj[firstNum] || 0) + 1;

  var stop = Object.keys(obj).find(function(e) {
    return obj[e] == 3;
  });
  if (stop) break;
}

console.log(obj);
console.log(ar);

Answer 4

To efficiently store and check the occurrence of each first number, you can utilize an object in JavaScript. In each iteration of a while loop, generate a random number for the first number and store it as a property in an object. Check if any value in this object equals 3 to break out of the loop.

var ar = [];
var obj = {}

while (true) {
  var firstNum = parseInt(Math.random() * 5) + 1;

  ar.push([firstNum, 1]);
  obj[firstNum] = (obj[firstNum] || 0) + 1;

  var stop = Object.keys(obj).find(function(e) {
    return obj[e] == 3;
  });
  if (stop) break;
}

console.log(obj);
console.log(ar);

Answer 5

Answer №3

One way to approach this problem is by creating a function that tracks the occurrence of numbers in the first column, incrementing a counter whenever a unique number is encountered. If the counter reaches 3, the algorithm stops pushing elements into an array and exits the loop.

Below is a sample implementation:

var data = ['-15, 1', '-15, 2', '2, 3', '2, 4', '2, 5', '77, 6', '22, 3'];

function findUnique(array) {
    var result = [], x, y, obj = {}, count = 0;

    for (let i = 0; i < array.length; i++) {
        let pair = array[i].split(',');
        x = parseInt(pair[0]);
        y = parseInt(pari[1]);

        if (count === 3) {
            break;
        }

        result.push([x, y]);

        if (!obj[x]) {
            obj[x] = 1;
            count++;
        }
    }
}

Answer 6

One way to approach this problem is by creating a function that tracks the occurrence of numbers in the first column, incrementing a counter whenever a unique number is encountered. If the counter reaches 3, the algorithm stops pushing elements into an array and exits the loop.

Below is a sample implementation:

var data = ['-15, 1', '-15, 2', '2, 3', '2, 4', '2, 5', '77, 6', '22, 3'];

function findUnique(array) {
    var result = [], x, y, obj = {}, count = 0;

    for (let i = 0; i < array.length; i++) {
        let pair = array[i].split(',');
        x = parseInt(pair[0]);
        y = parseInt(pari[1]);

        if (count === 3) {
            break;
        }

        result.push([x, y]);

        if (!obj[x]) {
            obj[x] = 1;
            count++;
        }
    }
}

Answer 7

Answer №4

This code demonstrates a unique push function:

let customArray={
   arr:[],
   push:function(obj){
     for(let a=0;a<this.obj.length){
     let count=0;
       for(let i=0;i<this.arr.length;i++){
          if(obj[a]!=this.arr[i][a]){
             count++;
             if(count==3){
                break;
             }
          }
        }
      }
     this.arr.push(obj);      
    };
 };

Now you can execute the following to push an array into customArray:

customArray.push([0,1,2]);

You can retrieve it using:

alert(customArray.arr);

However, direct access to customArray is no longer possible

Answer 8

This code demonstrates a unique push function:

let customArray={
   arr:[],
   push:function(obj){
     for(let a=0;a<this.obj.length){
     let count=0;
       for(let i=0;i<this.arr.length;i++){
          if(obj[a]!=this.arr[i][a]){
             count++;
             if(count==3){
                break;
             }
          }
        }
      }
     this.arr.push(obj);      
    };
 };

Now you can execute the following to push an array into customArray:

customArray.push([0,1,2]);

You can retrieve it using:

alert(customArray.arr);

However, direct access to customArray is no longer possible

JavaScript halt pushing when a distinct value is encountered

Answer №1

Answer №2

Answer №3

Answer №4

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