String Indices Swift 3

Question

I am beginner of Swift 3 and came across one example to retrieve a character using string indices. I do not have swift 3 installed but I doubt one thing that is different from explanation. I do not know, it is bug, writing mistake or what. Below is a example from page 166 of "The Swift Programming Language(Swift 3 beta)".

let greeting = "Guten Tag!"

greeting[greeting.startIndex] //Prints G according to text. Fine according to definition.

greeting[greeting.index(before:greeting.endIndex)] //Prints ! according to text. Now if you look at greeting String, the character before endIndex is g. It must print g according to definition.

greeting[greeting.index(after:greeting.startIndex)] //Prints u according to text and is right according to definition also.

Somebody can explain this behaviour?

Thorsten Dittmar · Accepted Answer · 2016-07-15 07:26:06Z

1

From the documentation in section "String Indices":

The endIndex property is the position after the last character in a String. As a result, the endIndex property isn’t a valid argument to a string’s subscript.

This means that endIndex is actually quite like the length of the string and the last character is at index endIndex - 1.

So the output is correct. Also, the same "Guten Tag!" example is given on that documentation page.

answered Jul 15, 2016 at 7:26

Thorsten Dittmar

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WasimSafdar Over a year ago

I will, after 7 minutes. :)

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