java.lang.NullPointerException Example – How to handle Java Null Pointer Exception

JCG Related Articles:

Sections:

00:00 - What null is
03:30 - Nullpointerexception example
04:45 - Ways to avoid/handle Nullpointerexception
05:00 - Check with if
07:20 - Ternary operator
11:20 - Throwing exception on null
12:45 - Optionals
15:50 - Nullpointerexception with Maps
19:10 - Assertion
21:00 - InstanceOf

Instructor Mike Møller Nielsen:
Mike was born in 1977 in Kolding / Denmark and he has a passion for programming and tech in general. He works on freelance basis mostly in Denmark where he develops full stack applications mostly written in Java with Spring Boot. He has a bachelor in Chemistry which he took before migrating to IT engineering. He has a YouTube channel where he spreads the knowledge and solutions to every day problems.

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#Java #JavaTutorial #JavaProgramming #LearnJava #Java.Lang.NullpointerException

[johnmcneil]

I was surprised by the content then I went back and re-read the title. I found the information informative and well presented so thank you for taking the time to produce this.

[julikim]

This video is amazing. You covered all the good examples of handling java null pointer exception. Thanks so much!!

[hardeepdhillon]

Please help I use samsung a7 mobile I have same problem help me

[vinijoncrafts]

Can someone help me to understand why is this getting null.pointer.exeption?

Ship Ship;
//PImage ship;
float x = 100;
float y = 100;
float vel = 1;
float aceleramento = 0.7;
float acelerar = 0.7;
int vel_maxima = 30;

void setup() {
size(1000, 1000);
//ship = loadImage("ship.png");
}

void draw() {
y += vel;
vel += acelerar;

background(255);
Ship.rotating();
Ship.actions();
}

class Ship {

void rotating() {
pushMatrix();
translate(x, y);
circle(x, y, 20);
rotate(degrees(0.0005 * vel));
rect(x, y, 150, 50);
popMatrix();
}

void actions() {
if (mousePressed) {
if (mouseButton == LEFT) {
acelerar = -aceleramento;
}
} else {
acelerar = aceleramento;
}

if (y > height - 87) {
y = height - 87;
vel = 0;
}

if (y < height - height) {
y = height - height;
vel = 0;
}

if(vel > vel_maxima) {
vel = vel_maxima;
}else if(vel < -vel_maxima) {
vel = -vel_maxima;
}

if (dist(height - height, height - height, y, y) < 30 && mousePressed) {
y = height - height;
vel = 0;
} else if (dist(height - 87, height - 87, y, y) < 30 && !mousePressed) {
y = height -87;
vel = 0;
}
}
}

Thanks!

[mr.RAND]

Some use ternary operator to check for null and if null it returns a default value.

[NBRIUM]

(nullableString, defaultString) ->

[MagDag_]

Thank you! P.S. IMHO Your intro too loud.

[MagDag_]

Why you didn't use a Try, catch? I'm beginner in QA automation

[Nusremmus]

Thank you for your try. Null errors are fake news no doubt. I listened to 5 min. of your video and if I didn't know what nulls were, I sure the hell don't now. Null pointer exceptions are the result of sloppy code. But I understand that we all make mistakes and miss something now and then. But fuck, this is not brain surgery.