Swift-二进制运算符'> ='不能应用于类型为'String'和'Int'的操作数

Question

Not really understanding why this isn't working. I'm pretty new to the Swift world.

The error I'm getting is Binary operator '>=' cannot be applied to operands of type 'String' and 'Int'

Could anyone help me understand why I'm getting this error? Do I need to convert the String to a Double or is there something else I'm totally missing? Again I'm new to Swift.

Answer 1

Do I need to convert the String to a Double?

Yes, that's basically it.

You must declare first a variable to accumulate all the inputs:

var inputs = [Double]()

Observe that I'm declaring an array of Double because that's what we are interested in.

Then, each time you ask the input, convert the obtained String to Double and store it in your array:

print("Please enter a temperature\t", terminator: "")
var message : String = readLine()!
let value : Double = Double(message)!
inputs.append(value)

Finally, check all the accumulated values in inputs (you got this part right):

for value in inputs {
    // value is already a Double
    if value >= 80 { 
        message = "hot!"
    }
    // etc.
}

I suggest researching how to convert to Double with error checking (ie how to detect "100 hot!" and ignore it because can't be converted).

Also, consider using a loop to read the values.