Equals ignore case Java

Two strings are considered equal ignoring case if they are of the same length and corresponding characters in the two strings are equal ignoring case. Two characters c1 and c2 are considered the same ignoring case if at least one of the following is true: The two characters are the same (as compared by the == operator)

Two strings are considered equal ignoring case if they are of the same length and corresponding characters in the two strings are equal ignoring case. Two characters c1 and c2 are considered the same ignoring case if at least one of the following is true: The two characters are the same (as compared by the == operator)

How do we check if a String contains a substring (ignoring case)…