case-insensitive

I need to check if a certain term exists within a string (in SQL it's something like like '%termo%'). The point is that I ne ... uim Pedro Soares"; mainStr.Contains("JOA"); mainStr.Contains("Quim"); mainStr.Contains("PEDRO"); mainStr.Contains("PeDro");

When I had this question, I did not find quick results in Portuguese that offered an answer(most of the results are in StackO ... ? if you search for a name with an accent it is possible that it identify that "Luis" is related to" Luis " and vice versa?

Talk guys good afternoon, I have a search field but I need it to return the values regardless of toLowerCase() and toUpperCas ... query) != -1){... I only succeed when I search for ball I need this function to be case insensitive, can anyone help me ?

Why, in PHP, some predefined constants are case-insensitive (do not differentiate uppercase from Lowercase) and others are no ... med 'php_EOL' As it turns out, in the latter case it generates error, and in the first one it does not generate any error!

Or is this just taste? Do not want if you like one more than the other. I don't care why people like one or the other more. ... do not understand the subject, I'm talking about the syntax of the language. I'm talking about the keywords, the identifiers.