You declared them, but you didn’t initialize them. Initializing them is setting them equal to a value:
int a; // This is a declaration a = 0; // This is an initialization int b = 1; // This is a declaration and initialization
You get the error because you haven’t initialized the variables, but you increment them (e.g., a++
) in the for
loop.
Java primitives have default values but as one user commented below
Their default value is zero when declared as class members. Local variables don’t have default values
Related Posts:
- Initializing multiple variables to the same value in Java
- Java: “error: cannot find symbol”
- How to initialize an array in Java?
- Initialize part of an array in java
- Initialization of an ArrayList in one line
- Java “Error occurred during initialization of VM” fix?
- Non-static variable cannot be referenced from a static context
- Non-static variable cannot be referenced from a static context
- Non-static variable cannot be referenced from a static context
- “No X11 DISPLAY variable” – what does it mean?
- Double array initialization in Java
- Java, “Variable name” cannot be resolved to a variable
- Java, “Variable name” cannot be resolved to a variable
- What is the difference between a local variable, an instance field, an input parameter, and a class field?
- Java, “Variable name” cannot be resolved to a variable
- accessing a variable from another class
- What is the default initialization of an array in Java?
- JAVA Variable declaration not allowed here
- What is the use of a private static variable in Java?
- Java: how to initialize String[]?
- In Java, how to assign the variable number=Integer.parseInt(args[0]) a value if no argument is passed?
- How can I initialize a LinkedList with entries/values in it?
- Static Initialization Blocks
- What is an
method in Java? Can it be overridden? - What does Java option -Xmx stand for? [duplicate]
- Finding white rectangle in an image
- How to use the toString method in Java?
- Unable to find valid certification path to requested target – error even after cert imported
- javac is not recognized as an internal or external command, operable program or batch file [closed]
- Java : Comparable vs Comparator [duplicate]
- Convert int to char in java
- Change date format in a Java string
- Converting String to “Character” array in Java
- Java – What does “\n” mean? [duplicate]
- must declare a named package eclipse because this compilation unit is associated to the named module
- Exception in thread “main” java.lang.StackOverflowError
- Best way to convert an ArrayList to a string
- How can I prevent java.lang.NumberFormatException: For input string: “N/A”?
- Compiled vs. Interpreted Languages
- How to round up to the next integer?
- Spring @PropertySources value not overriding
- Array ArrayList python equivalent
- Java ArrayList copy
- How do I apply the for-each loop to every character in a String?
- Session TimeOut in web.xml
- Java – removing first character of a string
- How to send a Map in JSON
- Getting java.lang.ClassNotFoundException: org.apache.commons.logging.LogFactory exception
- Explain the use of a bit vector for determining if all characters are unique
- What does the following Oracle error mean: invalid column index
- Sorting HashMap by values
- Will Arrays.sort() increase time complexity and space time complexity?
- Exception in thread “main” java.lang.NumberFormatException: For input string: “S”
- Java Console Prompt for ENTER input before moving on [duplicate]
- Maven: Failed to read artifact descriptor
- The system cannot find the file specified in java
- Java Generate Random Number Between Two Given Values
- Causes of getting a java.lang.VerifyError
- “Unmappable character for encoding UTF-8” error
- UnsatisfiedDependencyException: Error creating bean with name
- Random shuffling of an array
- How to convert int[] to Integer[] in Java?
- Why am I getting a “; expected” error?
- How/where to download openjdk/openjre for windows [duplicate]
- IO Error: The Network Adapter could not establish the connection
- How to create a directory in Java?
- Converting from Integer, to BigInteger
- Get a resource using getResource()
- Java comparing generic types
- Simplest way to read JSON from a URL in Java
- Display Animated GIF
- Why is my method undefined for the type object?
- An established connection was aborted by the software in your host machine tomcat jackson
- Generate a random double in a range
- How to open a new tab using Selenium WebDriver in Java?
- Selenium Webdriver: Element Not Visible Exception
- Whitespace Matching Regex – Java
- Unreachable code in eclipse
- “Field can be converted to a local variable” message appearing when setting Android ActionBar colour
- Convert an integer to an array of digits
- Google firebase check if child exists
- Android Emulator: Unfortunately App has stopped
- Can we execute a java program without a main() method? [duplicate]
- How to really read text file from classpath in Java
- Java command not found on Linux
- Selenium using Java – The path to the driver executable must be set by the webdriver.gecko.driver system property
- How to break out or exit a method in Java?
- Java Exception in thread “AWT-EventQueue-0” java.lang.NullPointerException
- Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/JDBC_DBO]]
- System.out.println function syntax in C++
- How to get Java to wait for user Input
- Java using enum with switch statement
- Removing double quotes from a string in Java
- What is inverse function to XOR?
- Java Swing revalidate() vs repaint()
- Append a single character to a string or char array in java?
- for each loop in groovy
- Details of difference between @see and @inheritDoc
- add string to String array
- Difference between System.getProperty(“line.separator”); and “\n”?