Question

Using HTML and JavaScript, receive a positive number, n, and output all prime numbers that are smaller than n and have a digit 7. For example, if n is 100, the program should output 7, 17, 37, 47, 67, 71, 73, 79, and 97.

Answer 1

CODE IN JAVASCRIPT:

const number=parseInt(prompt("Enter the value of n : ")); //this will create a dialogue box which prompts when we take input

if(number==1)

{

    console.log("The number is neither prime nor compsite")

}

for(let i=2; i<=number ;i++){ //checking for each integer between 2 to number

    var count=0; //if this count changes to 1 for a number then the number is not prime

    for(let j=2;j<=i/2;j++)

    {

        if(i%j==0)

        {

            count=1;

            break;

        }

       

    }

    if(count==0) //this means i is prime

    {

      var num=i; //this num is used to find all the integer with number 7

      while(num!=0)

      {

          if(num%10==7) //checking condition if there is 7 in the number

          {

              console.log(i);

              break;

          }

          num=num/10;

      }

    }

}

OUTPUT SNIPPET: