There's an 64 bit signed integer and I'm trying to read every 4 bits.

a := int64(1229782938247303441)
for i := 0; i < 16; i   {
    fmt.Printf("%v\n", byte(a) >> 4)
    a >>=  4 
}

The last value is 0 which should be 1.

CodePudding user response：

Use a & 0xf to get the bottom 4 bits. The value 0xf has a one bit in the lower four bits and zeros in all other bits.

a := int64(1229782938247303441)
for i := 0; i < 16; i   {
    fmt.Printf("%v\n", a & 0xf)
    a >>=  4 
}