如何检查inf？Swift xcode7

Question

如果计算结果不是无限的，我如何签入Swift？

我下面的代码在打印“dividepointsbyrest是inf”之后崩溃了。如果除法点被checks != 0“检查为零。‘如果除以does != inf’不起作用。

var dividepointsbyrest = (BPMpoints / restDouble)
    print("dividepointsbyrest is") 
    print(dividepointsbyrest) 

    var BPMpercentD = 100.0 * dividepointsbyrest

Answer 1

Double有一个isInfinite/isFinite属性。

if dividepointsbyrest.isInfinite {
    print("dividepointsbyrest is infinite")
}

或

if dividepointsbyrest.isFinite {
    print("dividepointsbyrest is finite")
}