What is the operator for?

Question

var n = prompt("Digite um numero");
if(n & 1){
    alert("Impar");
} else {
    alert("Par");
}
alert(n);

This code block is very simple, but the focus is on this operator &. What’s he good for? and in the code above he’s doing what n & 1?

Answer 1

According to the MDN:

Bit-to-bit operators are operators treated as 32 sequence bits ( zeros and ones ), preferably as decimal, hexadecimal, or octal numbers. For example, the decimal number 9 had as 1001 binary representation. Bit-to-bit operators perform operations on such binary representations, but return values numeric in the Javascript pattern

.

console.log(5 & 13); // 0101 & 1101 = 0101
// expected output: 5;

console.log(parseInt("0101",2) & parseInt("1101",2));
// expected output: 5;

console.log(5 & 13 & 3); // 0101 & 1101 & 0011 = 0001
// expected output: 1;

console.log(5 | 13); // 0101 | 1101 = 1101
// expected output: 13

....Operator...... Use......... Description

Bitwise AND........ a & b... Returns 1 at each bit position for which the

......................................... corresponding bit of both were 1s.

Source: Bitwise Operators