CODEWITHSUNDEEP
java
Abhigyan Singh
Abhigyan Singh

Reputation: 105

Java Identifier expected Semi-colon given : Variable naming conventions

Why can't I use variable names such as these in my Java code?

int 6q1, 6q2, 6q3, 6q4;
int 7q1, 7q2, 7q3, 7q4;
int 8q1, 8q2, 8q3, 8q4;

Error: Identifier Expected

Upvotes: 0

Views: 272

Answers (3)

Arc676
Arc676

Reputation: 4465

Variable names cannot start with numbers. They can only start with letters or (IIRC) underscores.

... 6q1, 6q2, 6q3, 6q4;

These are all invalid.

int 7q1, 7q2, 7q3, 7q4;
int 8q1, 8q2, 8q3, 8q4;

So are these.

Rename them to start with i or _.

From the documentation (italics and bold added by me for emphasis):

Every programming language has its own set of rules and conventions for the kinds of names that you're allowed to use, and the Java programming language is no different. The rules and conventions for naming your variables can be summarized as follows:

Variable names are case-sensitive. A variable's name can be any legal identifier — an unlimited-length sequence of Unicode letters and digits, beginning with a letter, the dollar sign "$", or the underscore character "_". The convention, however, is to always begin your variable names with a letter, not "$" or "_". Additionally, the dollar sign character, by convention, is never used at all. You may find some situations where auto-generated names will contain the dollar sign, but your variable names should always avoid using it. A similar convention exists for the underscore character; while it's technically legal to begin your variable's name with "_", this practice is discouraged. White space is not permitted.

Subsequent characters may be letters, digits, dollar signs, or underscore characters. Conventions (and common sense) apply to this rule as well. When choosing a name for your variables, use full words instead of cryptic abbreviations. Doing so will make your code easier to read and understand. In many cases it will also make your code self-documenting; fields named cadence, speed, and gear, for example, are much more intuitive than abbreviated versions, such as s, c, and g. Also keep in mind that the name you choose must not be a keyword or reserved word.

If the name you choose consists of only one word, spell that word in all lowercase letters. If it consists of more than one word, capitalize the first letter of each subsequent word. The names gearRatio and currentGear are prime examples of this convention. If your variable stores a constant value, such as static final int NUM_GEARS = 6, the convention changes slightly, capitalizing every letter and separating subsequent words with the underscore character. By convention, the underscore character is never used elsewhere.

Upvotes: 3

cat fierce mouse charming
cat fierce mouse charming

Reputation: 29

6q1, 6q2, 6q3, 6q4, 7q1, 7q2, 7q3, 7q4 8q1, 8q2, 8q3, 8q4;

Java variables should start with _ or a character. Variables are not allowed to start with a number.

Upvotes: 2

Abdelhak
Abdelhak

Reputation: 8387

Using ALL uppercase letters are primarily used to identify constant variables. Remember that variable names are case-sensitive. You cannot use a java keyword (reserved word) for a variable name.

For your variables an appropriate name like:

int numb7q1,. .,.,;

Upvotes: 1

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