Checks if the provided integer is a prime number.
Check numbers from 2
to the square root of the given number.
Return false
if any of them divides the given number, else return true
, unless the number is less than 2
.
代码片段
const isPrime = num => {
const boundary = Math.floor(Math.sqrt(num));
for (var i = 2; i <= boundary; i++) if (num % i === 0) return false;
return num >= 2;
};
使用样例
isPrime(11); // true