Question

How to check if all bits of a number are set in JavaScript

Answer 1

function get_bits(n) {
    return (n >>> 0).toString(2);
}
  
function is_all_bits_set(n) {
   return (n + 1) & n;
}
  
let n = 15;
  
console.log(get_bits(n));
console.log(get_bits(n + 1));
console.log(get_bits((n + 1) & n));
if (is_all_bits_set(n) === 0) {
    console.log("Yes");
} else {
    console.log("No");
}
  
console.log();  
  
n = 13;
  
console.log(get_bits(n));
console.log(get_bits(n + 1));
console.log(get_bits((n + 1) & n));

if (is_all_bits_set(n) === 0) {
    console.log("Yes");
} else {
    console.log("No");
}
 
 
 
/*
run:
    
"1111"
"10000"
"0"
"Yes"

"1101"
"1110"
"1100"
"No"
     
*/

 

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