Swift NSString 检查数字

Question

我有一个 Array:NSString 看起来像

[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
所以我尝试了

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

但由于 [0] 是一个字符串，它不应该是 return 0，因为它也可以是 [4]

0

有没有办法检查 NSString 是否只是一个数字（return 或 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：您可以使用 Int(<your variable>) 它 return 是数字，如果它可以投射，否则它 return 零，你可以检查 returned 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")
}

这个例子应该return"it is not a number"

Answer 2

如果要收集数组元素为数字的索引，可以使用映射并返回元素可以转换为数字的索引。

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([=10=] as String) != nil }
print("numbers: \(numbers)")

Swift NSString 检查数字

Swift NSString check for Numbers

numbers

nsstring

ios

swift