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[HD Pg 0, Sec. 13.3.5 - important-methods-of-arraylist]

Posted: Tue Nov 05, 2019 12:03 pm
by demetrio
I tried to run the example in page 340 and I got "boolean cannot be dereferenced". Is that what you mean by "Method chaining: Unlike StringBuilder, none of the ArrayList methods return a reference to the same ArrayList object. Therefore, it is not possible to chain method calls"? Kindly, see tentative bellow.

Deshmukh, Hanumant. OCP Oracle Certified Professional Java SE 11 Programmer I Exam Fundamentals 1Z0-815: Study guide for passing the OCP Java 11 Developer Certification Part 1 Exam 1Z0-815 (p. 340). Enthuware. Edição do Kindle.

jshell> var al = new ArrayList < Integer >();
...> al.add( 1).add( 2);
al ==> []
| Error:
| boolean cannot be dereferenced
| al.add( 1).add( 2);
| ^------------^

jshell> all.add(1);
| Error:
| cannot find symbol
| symbol: variable all
| all.add(1);
| ^-^

jshell> al.add(1);
$3 ==> true

jshell> al.add(1).add(2);
| Error:
| boolean cannot be dereferenced
| al.add(1).add(2);
| ^-----------^

jshell> al.add(2);
$4 ==> true

jshell> System.out.println(al);
[1, 2]

Re: [HD Pg 0, Sec. 13.3.5 - important-methods-of-arraylist]

Posted: Tue Nov 05, 2019 7:39 pm
by admin
Correct.
Compare it to stringBuilder.append("a").append("b");