function toBinFormat(binary_value, n) {
for (let i = 0; i < 8; i++) {
binary_value[i] = n & 0x80 ? '1' : '0';
n <<= 1;
}
}
const value = 7;
const arr = [0,0,0,0,0,0,0,0];
toBinFormat(arr, value);
console.log(value + ' = ' + arr);
/*
run:
"7 = 0,0,0,0,0,1,1,1"
*/