- JavaScript prime number program
- In this example will learn about how to find the number is prime or not.
- WHATS IS PRIME NUMBER
- A number greater than 1 with exactly two factors is called prime number.
- Number which is divisible by 1 and itself is prime number. If it is divisible by any other number(other than 1 and itself) then it's not a prime number.
- Consider an example of number 5 ,Which has only two factors 1 and 5. This means 5 is a prime number. Lets take one more example Number 6, which has more than two factors, i.e 1,2,3. This means 6 is not a prime number.
- The first ten prime numbers are 2,3,5,7,11,13,17,19,23,29.
- Note: It should be noted that 1 is non-prime number, because in the above defination already mentioned A number greater than 1 with 2 factors called prime number..
- Here we have simple program to print the prime numbers in java script.
JavaScript program to check a number is prime number or not.
- <html>
- <head>
- <script>
- // javascript program to check the number is prime or not.
- // prime number program in javascript
- // javascript prime number program
- // take input from the user
- const x = parseInt(prompt("Enter a number to check prime or not: "));
- let isPrimeNumber=true;
- // check if number is equal to 1
- if (x === 1) {
- alert("1 is neither prime nor composite number.");
- }
- // checking if number is greater than one or not
- else if (x > 1) {
- // iterating from 2 to number -1 (leaving 1 and itself )
- for (let i = 2; i < x ; i++) {
- if (x % i == 0) {
- isPrimeNumber = false;
- break;
- }
- }
- if (isPrimeNumber) {
- alert(`${x } is a prime number`);
- } else {
- alert(`${x } is not a prime number`);
- }
- }
- // check if number is less than 1
- else {
- console.log("The number is not a prime number.");
- }
- </script>
- </head>
- <body>
- </body>
- </html>
Output:
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