Question

我有一个看起来像

的数组：NSString

[X1],[Tester],[123],[456],[0]

现在我必须检查一个位置（总是相同的）是数字还是字符串
所以我试过

 var test = Array[0].intValue
        print(test)

但是[0]是一个字符串，它不应该返回0，因为它也可能是[4]

0

有没有办法检查NSString是否只是一个数字（返回true / false就足够了）？

完整代码示例

var Array: [NSString] = ["X1","Fabian","100","200","not avaible"]
/* could also be Array:
var Array0: [NSString] = ["X2","Timo","200","300","300"]
*/
//need to check if Array[4] is a number or not so its "text" or "number"

var test = Array[4].intValue
print(test)

//return 0

Answer 1

在swift2中：你可以使用Int(<your variable>) 如果它可以强制转换它返回数字，否则它返回nil，你可以检查返回的值。

使用可选条件的示例：

let s = "Some String"
if let _ = Int(s) {
    print("it is a number")
}else{
    print("it is not a number")
}

此示例应返回＆＃34;它不是数字＆＃34;

Answer 2

如果您想收集数组元素为数字的索引，您可以使用映射并返回可以将元素转换为数字的索引。

var Array0: [NSString] = ["X1","Fabian","100","200","not avaible"]
var numbersAt: [Int] = Array0.enumerate().map{ (index, number) in
    return (Int(number as String) == nil ? -1 : index)  
}
print("indexes: \(numbersAt)") //numbersAt will have the indexes unless they're not numbers in which case it'll have -1

//Another option will be to filter the array and collect only the number strings 
var numbers = Array0.filter { Int($0 as String) != nil }
print("numbers: \(numbers)")

Swift NSString检查Numbers

2 个答案: