If the argument is negative infinity or any value less than or equal to the value of Integer. If the argument is positive infinity or any value greater than or equal to the value of Integer. Returns the trigonometric sine of an angle. Returns the square root of a double value. Once you instantiate a String Object with a set of characters, you can't change its size or replace its characters, in effect the String becomes a constant.
Strings are immutable.
But the comparison ignores case. Concatenates the specified string to the end of this string. Returns the index within this string of the last occurrence of the specified character. Java creates String object instead of modifying the original. So Java would be constantly creating new objects, eating up memory and time.