what does ios dev NSPredicate "title CONTAIN[c]". the [c] mean?

In iOS development, the NSPredicate expression title CONTAIN[c] is used to filter objects based on a specific property. In this case, the property being filtered is title.

The CONTAIN[c] operator is a case-insensitive comparison operator. It means that the predicate will match objects where the title property contains the specified string, regardless of whether the characters are in uppercase or lowercase.

Here's a breakdown of what each part means:

title: This is the name of the property that will be compared.
CONTAIN: This is the comparison operator, which checks if the specified string is contained within the property value.
[c]: This modifier indicates that the comparison should be case-insensitive.
For example, if you have an array of objects with a title property, and you want to find all objects where the title contains the string "apple", you could use the following NSPredicate:

NSPredicate *predicate = [NSPredicate predicateWithFormat:@"title CONTAINS[c] %@", @"apple"];
NSArray *filteredArray = [myArray filteredArrayUsingPredicate:predicate];

This would return a new array containing only the objects whose title property contains the string "apple", regardless of whether it's written as "apple", "Apple", or "APPLE".