Why to use 'import' in java?

Answer 1

The import statement in Java allows to refer to classes which are declared in other packages to be accessed without referring to the full package name. You do not need any import statement if you are willing to always refer to java.util.List by its full name, and so on for all other classes. But if you want to refer to it as List, you need to import it, so that the compiler knows which List you are referring to.

Classes from the java.lang package are automatically imported, so you do not need to explicitly do this, to refer to String, for example.

Answer 2

The java import keyword is used to import already existing classes in Java, into our program.

for ex: in our program if we say import java.util.*; it means we are importing all the classes inside the package java.util into our current class and we can use those classes here.

If you try to use any external class without importing it, you will get a compile time error. The import keyword tells the compiler the places where it has to look for external class references.

Answer 3

Using an import statement allows you to use classes from other packages without fully qualifying them. For example, if you wanted to instantiate a new ArrayList object without an import statement, you would need to do this: java.util.ArrayList foo = new java.util.ArrayList(); If you use an import statement like this: import java.util.ArrayList; You can then instantiate an ArrayList object like this: ArrayList foo = new ArrayList(); The import statement can also be used to import an entire package, instead of only one class. For example, the above import statement could be rewritten like this: import java.util.*;