取整

• 向上取整 ceil(a) 返回不小于变量a的最小整数值

let a1:Float = 1.1
let a2:Float = 1.5
let a3:Float = 1.8
print("ceil a1 : \(ceil(a1)) & ceil a2 : \(ceil(a2)) & ceil a3 : \(ceil(a3))")

/// Debug Log
/// ceil a1 : 2.0 & ceil a2 : 2.0 & ceil a3 : 2.0

• 向下取整 floor(a) 返回不大于变量a的最大整数值

let a1:Float = 1.1
let a2:Float = 1.5
let a3:Float = 1.8
print("floor a1 : \(floor(a1)) & floor a2 : \(floor(a2)) & floor a3 : \(floor(a3))")

/// Debug Log
/// floor a1 : 1.0 & floor a2 : 1.0 & floor a3 : 1.0

• 四舍五入 round(a)返回变量a的四舍五入整数值

let a1:Float = 1.1
let a2:Float = 1.5
let a3:Float = 1.8

print("ceil a : \(round(a1)) & ceil a : \(round(a2)) & ceil a : \(round(a3))")

/// Debug Log
/// round a1 : 1.0 & round a2 : 2.0 & round a3 : 2.0