" Hello World "
with the leading and trailing spaces. Some would expect a trimmed "Hello World".
So, what concepts does this question try to test?
What follow on questions can you expect?
If you want the above code to output "Hello World" with leading and trailing spaces trimmed then assign the s.trim( ) to the variable "s". This will make the reference "s" to now point to the newly created trimmed String object.
The above code can be rewritten as shown below
StringBuilder sb = new StringBuilder(" Hello "); sb.append(" World "); System.out.println(sb.toString().trim( ));
The StringBuilder is not a thread-safe class. It is fine when you are using it as a local variable. If you want to use it as an instance variable then use the StringBuffer class which is thread-safe. If you are curious to know what happens under the covers during String manipulation -- String concatenation
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