Loops & BinaryGap

Get All Prime Numbers from 0 to x

● script.js:

 function getAnswer(x)
{
    if(x !== parseInt(x)) {return 'numbers only'}    
    
    var number = [];
    
     var prime = [];
     
 for (i =2; i <= x; ++i)
 {
   if(!number [i])   
     { 
       prime.push(i);   
       
        for (j = i << 1; j <= x; j += i)
        {
        number[j] = true;
        }                                 
     }    
 }   
  
 return prime;
}

● index.html:

var x = prompt('Enter a number and get all prime numbers in range');
alert(getAnswer(parseInt(x)));

Are We There Yet ?

In this exercise I need to display the message 'Are we there yet ?' until user input is yes or yeah.

● script.js:

function thereYet(y)
{
  if (y === 'yes' || y === 'yeah')  // if input is yes or yeah alert yayy
  {alert('yayy');} 
  
  else       // if not return 'are we there yet ?' until input is yes/yeah
  {
     while(true)
      {
        var j = prompt('are we there yet ?');  

         if (j === 'yes' || j === 'yeah')
         {
             alert('yayy');
             break;
         }         
      }   
   }  
}

● index.html:

var y = prompt('Are we there yet ?');
thereYet(y);

Get The Longest Binary Gap of a Certain Value

In this exercise I need to find the longest binary gap of a certain value,

Finding the binary gap meaning I need to find the most zero values between two 1's and return the longest binary gap of the given value.

For example, 1041 in binary is 10000010001. the "gap" is the zero values between the two 1's. count the longest "gap" between the 1's and its 5

● script.js:

function binGap(num)
{
    if(num !== parseInt(num)) {return 'numbers only'}
  
    const binNum = num.toString(2);      // toString(2) converts the number to binary format, when used on a number
                                         // return the binary equivalent of the numeric value.
  
    const array = binNum.split('1').map((binGap, index, binArr) => // split the binary string we obtained using '1',
                                                                  // creating an array of empty strings,
                                                                 // iterate through the array with .map()
    {                                                           // and subject each item to a condition.
                                                                   
    return binArr[index + 1] != undefined ? binGap.length : 0; // return length of empty string or zeros
                                                              // if the value at the next index (index + 1) within the array is not undefined.
    });                                                      // if the value of the next index is undefined return 0.
     
    
    return Math.max.apply(Math, array);    // return the number of the longest binary gap.                                         
}

● index.html:

var z = prompt('Enter a number and get its binary gap');
alert(binGap(parseInt(z)));