java - 如何在 Java 中逐位读取整数？

Question

我想将 int 作为输入，并返回第 k 位。

int getBit(int n, int k){
    return kth bit in n;
}

我该怎么做？

Answer 1

使用位运算符:

int getBit(int n, int k) {
    return (n >> k) & 1;
}

解释(位):

n
100010101011101010 (example)
n >> 5
000001000101010111 (all bits are moved over 5 spots, therefore
&                   the bit you want is at the end)
000000000000000001 (0 means it will always be 0,
=                   1 means that it will keep the old value)
1