C#•2y ago

-1 in array?

I was using Array, and I find a code like that. The goal is to omit the periods and print the sentences line by line.
mystring[] = mystrings[2](“I like pizza.I like salad.”, “I like three of them.”)
…
while (periodLocation ! = -1)
…

I don’t know why or how it can has a value as -1…. doesn’t the location start from 0?

this is from Microsoft Learn and I didn’t find any tips that explains that. If this is confusing, I can copy the whole code here

Buddy•6/6/24, 7:36 PM

and periodLocation is?

Buddy•6/6/24, 7:37 PM

If it uses IndexOfIndexOf then -1-1 means it isn't found.
Because returning 0 would not make sense since it is a valid index

BBuddy and periodLocation is?

twistw00dOP•6/6/24, 8:34 PM

the location of the period! it basically asks where the location of the period is to separate the sentences. Thank you!

Ttwistw00d the location of the period! it basically asks where the location of the period i...

Buddy•6/6/24, 8:35 PM

huh?

Buddy•6/6/24, 8:36 PM

The only reason would be if they had a method or something that returned -1 if the index wasn't found.
Which as previously mentioned IndexOfIndexOf does.

Ttwistw00d I was using Array, and I find a code like that. The goal is to omit the periods ...

SWR•6/6/24, 8:53 PM

Sharing the actual code sample might help. Also yeah, it sounds like it's using the String.IndexOf method, which returns -1 if it cannot find a match to some string pattern

twistw00dOP•6/9/24, 5:38 AM

string[] myStrings = new string[2] { "I like pizza. I like roast chicken. I like salad", "I like all three of the menu choices" };
int stringsCount = myStrings.Length;

string myString = "";
int periodLocation = 0;

for (int i = 0; i < stringsCount; i++)
{
myString = myStrings[i];
periodLocation = myString.IndexOf(".");

string mySentence;

// extract sentences from each string and display them one at a time
while (periodLocation != -1)
{

// first sentence is the string value to the left of the period location
mySentence = myString.Remove(periodLocation);

// the remainder of myString is the string value to the right of the location
myString = myString.Substring(periodLocation + 1);

// remove any leading white-space from myString
myString = myString.TrimStart();

// update the comma location and increment the counter
periodLocation = myString.IndexOf(".");

Console.WriteLine(mySentence);
}

mySentence = myString.Trim();
Console.WriteLine(mySentence);
}

twistw00dOP•6/9/24, 5:38 AM

that was the solution code

Ttwistw00d string[] myStrings = new string[2] { "I like pizza. I like roast chicken. I like...

Buddy•6/9/24, 6:04 AM

So it was using IndexOf

Buddy•6/9/24, 6:04 AM

Which is what I said.