Difference between String.length() and String.getBytes().length
java, string
Solution
String.length()
`String.length()` is the number of 16-bit UTF-16 code units needed to represent the string. That is, it is the number of `char` values that are used to represent the string and thus also equal to `toCharArray().length`. For most characters used in western languages this is typically the same as the number of unicode characters (code points) in the string, but the number of code point will be less than the number of code units if any UTF-16 surrogate pairs are used. Such pairs are needed only to encode characters outside the BMP and are rarely used in most writing (emoji are a common exception).
String.getBytes().length
`String.getBytes().length` on the other hand is the number of bytes needed to represent your string in the platform's default encoding. For example, if the default encoding was UTF-16 (rare), it would be exactly 2x the value returned by `String.length()` (since each 16-bit code unit takes 2 bytes to represent). More commonly, your platform encoding will be a multi-byte encoding like UTF-8.
This means the relationship between those two lengths are more complex. For ASCII strings, the two calls will almost always produce the same result (outside of unusual default encodings that don't encode the ASCII subset in 1 byte). Outside of ASCII strings, `String.getBytes().length` is likely to be longer, as it counts bytes needed to represent the string, while `length()` counts 2-byte code units.
Which is more suitable?
Usually you'll use `String.length()` in concert with other string methods that take offsets into the string. E.g., to get the last character, you'd use `str.charAt(str.length()-1)`. You'd only use the `getBytes().length` if for some reason you were dealing with the array-of-bytes encoding returned by `getBytes`.
Problem
I am beginner and self-learning in Java programming. So, I want to know about difference between `String.length()` and `String.getBytes().length` in Java. What is more suitable to check the length of the string?