The Daily Brain Fart - LastIndexOf broken? Oh, no, 'tis me.
Often, in the scope of writing massively scalable enterprise systems that manage your finances, I parse strings. Mostly in my spare time.
What's happening here? I was reminded today that the start index passed to LastIndexOf() was from the ass-end of the string. I then lamented the obviousness of this and was then humbled by the silent-but-deadly odor my own brain fart.
I'm glad you're that much more confident in my abilities after reading this post. Up with TDD! Down with ADD!
public static void Main()
{
int newlineIndex = -1;
string x = "bob\neric\nfred\nted";
string z = "bob\r\neric\r\nfred\r\nted";
newlineIndex = x.LastIndexOf('\n',0);
Console.WriteLine(newlineIndex); //Expect 13, always get -1
newlineIndex = z.LastIndexOf('\n',0);
Console.WriteLine(newlineIndex); //Expect 16, always get -1
newlineIndex = x.LastIndexOf('\n');
Console.WriteLine(newlineIndex); //Expect 13, get 13
newlineIndex = z.LastIndexOf('\n');
Console.WriteLine(newlineIndex); //Expect 16, get 16
//Fart realized...
newlineIndex = x.LastIndexOf('\n',x.Length-1);
Console.WriteLine(newlineIndex); //Expect 13, always get 13
newlineIndex = z.LastIndexOf('\n',z.Length-1);
Console.WriteLine(newlineIndex); //Expect 13, always get 13
}
About Scott
Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.
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