表达式解析为未使用的I值

Question

I am new to Swift and I am trying to change background colour of button.

I am using chicken1 to change the background colour of the button all together

But I keep getting this error

Expression resolves to unused I Value"

Here is the current code.

let chicken1 = button1; button2
chicken1.backgroundColor = UIColor.blueColor()

Also should I use 'var' insted?

Answer 1

AFAIK, this isn't possible the way you are trying to do it.

One option is to loop through all of your buttons and change the background color in the loop.

for button in [button1, button2]{
    button.backgroundColor = UIColor.blueColor()
}

---

The reason you are getting this error is because this line

let chicken1 = button1; button2

is the same as

let chicken1 = button1
button2 //this value isn't used

Swift doesn't actually need ; at the end of a line like in other languages. By adding ; , you tell Swift that you want to have multiple expressions on a single line.

The second line doesn't do anything because there are no function calls and no assignment, so it's like you want to get the value of button2 but you don't use it.

Answer 2

As Arc676 mention into comment you can't assign multiple values to a single variable.

So first way to achieve that is you can set background color individually as shown below:

button1.backgroundColor = UIColor.blueColor()
button2.backgroundColor = UIColor.blueColor()

Or if you have array of button:

let chicken1 = [button1, button2]
for item in chicken1 {

    item.backgroundColor = UIColor.blueColor()
}

Answer 3

for Swift 3 Xcode 8 use the code below

button1.backgroundColor = UIColor.blue
button2.backgroundColor = UIColor.blue

Or if you have array of button:

let chicken1 = [button1, button2]
for item in chicken1 {
    item.backgroundColor = UIColor.blue
}