Interview Q&A / Java
Java interview questions
Collections, the JVM, strings, exceptions and threads, the backbone of most campus placement rounds.
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- What does the intern() method of String do?
intern() returns the pooled copy of a string. If the pool already holds an equal string it returns that one, otherwise it adds this string to the pool and returns it, so interned strings with equal text compare equal with ==.
IntermediateQuick answer1 min read - Why is a char array recommended over String for storing passwords in Java?
A String is immutable and may stay in memory until garbage collection, so it cannot be wiped. A char array can be overwritten with blanks right after use, which shrinks the time a password sits in memory where a heap dump could expose it.
IntermediateQuick answer1 min read