Using contains() method in java

Question

1.00/5 (1 vote)

See more:

Can i use contains() to check if an element i m trying to insert in an Arraylist is already there?

protected void addTeacher(Teacher t){
if (!(teacherList.contains(t)))
teacherList.add(t);
}

Thanks!

What I have tried:

Searching concrete examples in websites related to coding

Posted 1-Dec-18 15:39pm

Member 14002893

Updated 7-Dec-18 5:18am

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Patrice T · Answer 1 · 2018-12-01T15:48:00

Solution 1

Quote:
Searching concrete examples in websites related to coding

You should learn to use Google by yourself.
here is the first answer: Java.lang.String.contains() Method Example[^]

Posted 1-Dec-18 15:48pm

Patrice T

Chris Copeland · Answer 2 · 2018-12-07T05:19:00

An important thing to remember when using methods like contains(), indexOf() is that these sort of methods rely on using the equals() method to compare object types.

In your scenario, you're trying to see whether a list contains an instance of Teacher, so you may need to consider overriding the equals() method to check for equality in the objects. This page[^] has a good description.