Where to put variables/constants

Question

Created Apr ’22

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Hi there! I have a public structure and I called it in my ContentView, but I can't understand where to punt the var/let. I try to put them before "var body: some view" but it gives me these errors.

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Answer 1

Claude31 OP

Apr ’22

I would write either:

public struct Block: View {
    
    let size : CGFloat = 0  // or var
    let color: Color = .red  // or var
    
    public init() { // init not needed
    }
    
    public var body : some View {
        Text("Hello")
    }
    
}

or

public struct Block: View {
    
    let size : CGFloat  // or var
    let color: Color  // or var
    
    public init() {
        size = 0
        color = .red
    }
    
    public var body : some View {
        Text("Hello")
    }
    
}

Note that a constant (let) cannot be modified but can be set in init(), if not set before.

So, this fails:

public struct Block: View {
    
    let size : CGFloat = 0
    let color: Color = .red
    
    public init() {
        size = 0          // error Immutable value 'self.size' may only be initialized once
        color = .red          // error Immutable value 'self.color' may only be initialized once
    }
    
    public var body : some View {
        Text("Hello")
    }
    
}

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