【Swift 60秒】02 - Strings and Integers

0x00 Lesson

Swift is what’s known as a ​​type-safe​​ language, which means that every variable must be of one specific type. The str variable that Xcode created for us holds a string of letters that spell ​​“Hello, playground”​​, so Swift assigns it the type String.

On the other hand, if we want to store someone’s age we might make a variable like this:

var age = 38

That holds a whole number, so Swift assigns the type Int - short for integer".

If you have large numbers, Swift lets you use ​​underscores​​ as thousands separators - they don’t change the number, but they do make it easier to read. For example:

var population = 8_000_000

Strings and integers are different types, and they ​​can't​​ be mixed. So, while it’s safe to change str to “Goodbye”, I ​​can't​​​ make it ​​38​​ because that’s an Int not a String.

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0x01 Tips

Strings are ​​case sensitive​​, which means “Swift” is not the same string as “swift”.

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0x02 我的小作品

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