Consider the following code: let mask = !(0xF0 >> (pos % 2));
In this code, 0xF0 represents the binary value 0b11110000. When pos is even, (pos % 2) equals 0. Therefore, the right shift operation on 0b11110000 by 0 does not change the value, resulting in mask = 0b00001111.
However, when pos is odd, (pos % 2) equals 1. In this case, the right shift operation on 0b11110000 by 1 results in 0b01111000, which is incorrect.
*To fix this issue, modify the code to `let mask = !(0xF0 >> (pos % 2) 4);`.**
With this modification, when pos is even, (pos % 2) equals 0, and the right shift operation by 0 * 4 = 0 does not change the value, resulting in mask = 0b00001111.
Similarly, when pos is odd, (pos % 2) equals 1, and the right shift operation by 1 * 4 = 4 correctly results in 0b00001111, giving mask = 0b11110000.
caemor
commented
3 weeks ago
Consider the following code:
let mask = !(0xF0 >> (pos % 2));In this code,
0xF0represents the binary value0b11110000. Whenposis even,(pos % 2)equals0. Therefore, the right shift operation on0b11110000by0does not change the value, resulting inmask = 0b00001111. However, whenposis odd,(pos % 2)equals1. In this case, the right shift operation on0b11110000by1results in0b01111000, which is incorrect.*To fix this issue, modify the code to `let mask = !(0xF0 >> (pos % 2) 4);`.**
With this modification, when
posis even,(pos % 2)equals0, and the right shift operation by0 * 4 = 0does not change the value, resulting inmask = 0b00001111.Similarly, when
posis odd,(pos % 2)equals1, and the right shift operation by1 * 4 = 4correctly results in0b00001111, givingmask = 0b11110000.