Using Double in Switch Statement

问题

All of the values below are doubles, yet switch requires a integer value. Is there anyway around this?

switch(fivePercentValue){
case floor((5*fivePercentValue) / 100):
    fivePercent_.backgroundColor = [UIColor greenColor];
    fivePercentLabel_.textColor = [UIColor greenColor];
    break;
case ceil((5*fivePercentValue) / 100):
    fivePercent_.backgroundColor = [UIColor greenColor];
    fivePercentLabel_.textColor = [UIColor greenColor];
    break;
default:
    fivePercent_.backgroundColor = [UIColor redColor];
    fivePercentLabel_.textColor = [UIColor redColor];
    break;

回答1:

You are probable better of just using if else and testing for ranges but you can perform some maths on you fivePercentValue and then convert it to a integer so that different integers represent different ranges for example

switch( (int)(value*10.0) )
{
    case 0:        // this is 0.0 <= value < 0.1
        break;
    case 1:        // this is 0.1 <= value < 0.2
        break;
    case 2:        // this is 0.2 <= value < 0.3
        break;
    ....
}

来源：https://stackoverflow.com/questions/12398719/using-double-in-switch-statement