-29 struct ios sprite-kit swift swift2
struct Physics {
static let smallCoin : UInt32 = 0x1 << 1
static let smallCoin2 : UInt32 = 0x1 << 2
static let ground : UInt32 = 0x1 << 3
}
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那是什么意思
UInt32 = 0x1 << 1?
和静态让?
<<
是左移算子.您可以更好地以二进制形式显示它:
1 0000 0001
<< 1 ^ shift this one bit to the left
---- = ---------
2 0000 0010
1 0000 0001
<< 2 ^ shift this two bits to the left
---- = ---------
4 0000 0100
3 0000 0011
<< 2 ^ shift this two bits to the left
---- = ---------
12 0000 1100
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要记住的另一个属性是x << n = x * (2^n)
.相反的<<
是>>
- 右移操作员.