[appB] Examples for var

package appB;

import java.io.IOException;

import java.nio.file.Paths;

import java.util.ArrayList;

import java.util.List;

import static java.nio.file.Files.newBufferedReader;

import static java.nio.file.Paths.get;

public class VarLVTI {

  void simpleVar() {

    var name = "A Name";

    var names = new ArrayList<>();

  }

  void varFromMethodCall() {

    var customers = getCustomers();

  }

  void varMustBeDefinedStraightAway() {

    // invalid

//    var name;

    var someValue = 1;

    // invalid

//    someValue = "String";

  }

  void considerVariableNames() throws IOException {

    // descriptive names

    var reader = newBufferedReader(get("/"));

    //unhelpful names

    var stuff = doTheThing();

  }

  void programmingToInterface() {

    // need to declare the interface on the left hand side

    List<String> list1 = new ArrayList<>();

    // list2 is an ArrayList

    var list2 = new ArrayList<String>();

  }

  void doNotUseWithDiamondOperator() {

    // this is an ArrayList of Objects

    var list = new ArrayList<>();

  }

  private List<Customer> getCustomers() {

    return null;

  }

  private class Customer {

  }

  private String doTheThing() {

    return null;

  }

}