【Swift 60秒】06 - Constants

0x00 Lesson

I already said that ​

​variables​

​​ have that name because their values can ​

​change​

​​ over time, and

that is often useful. However, very often you want to set a value ​​

​once​

​​ and ​

​never​

​ change it, and so we have an alternative to the var keyword called let.

The let keyword creates ​

​constants​

​​, which are values that can be ​

​set once and never again​

​.

For example:

let taylor = "swift"      

If you try to change that, Xcode will refuse to run your code. It’s a form of safety: when you use constants you can no longer change something by accident.

When you write your own Swift code, you should always use let unless you specifically want to change a value. In fact, Xcode will warn you if you use var then don 't change the variable.

0x01 Tips

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