我不知道如何让它们加减，有一种方法可以做到这一点。基本上我想要1"+"3 =4，但我得到的是1+3
我不知道如何让它们加减，有一种方法可以做到这一点。基本上我想要1"+"3 =4，但我得到的是1+3
提问于 2017-02-15 14:29:28
let randsign = Int(arc4random_uniform(2) + 1)
//This function returns a random operator
func whatSign(par1:Int)-> String {
if (par1 == 1){
return "+"
}
else {
return "-"
}
}
var sigh = whatSign(par1: randsign)
let randnum1:Any = Int (arc4random_uniform(10) + 1)
let randnum2:Int = Int (arc4random_uniform(10) + 1)//我想让finVal变量进行数学运算，但因为sign变量是字符串，所以不需要
let finVal = "\(randnum1)\(sigh)\(randnum2)"
print(finVal)
//When I print I get for example 1-3, 9-4, 8+2 .But I wanted them to do arithmetic 回答 2
Stack Overflow用户
发布于 2017-02-15 14:35:41
NSExpression是评估数学的好方法之一
let finVal = "(randnum1)(sigh)(randnum2)"
let result = NSExpression(format: finVal).expressionValue(with: nil, context: nil) as! IntStack Overflow用户
发布于 2017-02-15 14:36:58
let randsign = Int(arc4random_uniform(2) + 1)
let randnum1:Any = Int (arc4random_uniform(10) + 1)
let randnum2:Int = Int (arc4random_uniform(10) + 1)
var finVal:Int
//This function returns a random operator
func whatSign(par1:Int)-> String {
//I want to compute the variables and get final result from adding or subtracting them
if (par1 == 1){
finVal = randnum1 + randnum2
return "+"
}
else {
finVal = randnum1 - randnum2
return "-"
}
}
whatSign(par1: randsign)
print(finVal)
//When I print I get for example 1-3, 9-4, 8+2 .But I wanted them to do arithmetic 也许它会对你有帮助
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/42242139
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