Learning how to code accurately and quickly offers several benefits. Aside from making you more employable in today’s tech-driven job market, coding also hones your problem-solving skills and fosters creativity.
But before you can build the next revolutionary app or software that will disrupt the tech space, you’ll need to master programming fundamentals. One of these fundamentals is syntax.
But what exactly is syntax in programming? In this article, you’ll discover how syntax rules govern the structure of programming languages, the major components of syntax, how to prevent syntax errors, and much more.
What Is Syntax in Programming?
In linguistics, syntax refers to the rules that govern the formation of grammatically correct sentences. Similarly, in computer programming, syntax refers to the rules that govern the structure of the symbols, words, and punctuation found in programming languages.
If the languages we spoke had no syntax, meaning and comprehension would quickly break down because everyone would have to make up their own rules about word order and sentence construction. “Dan bought a new jacket” could easily become “Bought a jacket new Dan,” which doesn’t make any sense.
Similarly, the syntax found in programming languages defines what the various combinations of symbols mean. The syntax also identifies the valid keywords and symbols that a programmer can use to write their source code. And the same way that grammatical rules govern each human language, unique syntax governs each programming language.
However, computers are very exacting when it comes to reading code. It’s why programmers need to write their code very carefully to adhere strictly to their programming language’s syntax. Any deviations from the syntax would lead to a syntax error, and the computer won’t be able to run the code.
Why Is Syntax Important in Programming?
To master a programming language, you’ll need to understand its syntax. Writing code according to the established structural rules makes it easier for both machines and humans to understand (a concept known as code readability).
Readable code is self-explanatory and is easily understood by different people. This fosters collaboration and innovation. Your colleagues could improve your code and programmers who wish to update your code in the future would have an easier task if your code is clean and readable.
Readable code adheres to the four C’s of coding: code integration, communication, consistency, and clarity.
Here’s a breakdown of each code quality metric:
- Code Integration – Readable code can be readily understood by compilers and interpreters. A compiler is a computer program that translates code written in one programming language into another programming language. An interpreter, meanwhile, executes programming languages like Python and Java at runtime.
- Communication – Well-written code is self-explanatory, leaving no room for confusion or ambiguity. This is especially important for open source projects where different collaborators need to share, merge, and update the code.
- Consistency – Code is consistent when it adheres faithfully to the established syntax (e.g. consistent use of punctuation and the naming of objects and variables). This facilitates predictable outcomes and makes the code easier to understand.
- Clarity – Since all code is basically a set of instructions, it helps a lot when you clearly communicate the instructions. In other words, readable code communicates its function and intent clearly.
The Major Components of Syntax in Programming
In computer programming languages, syntax is broadly broken down into three levels:
- Words – This lexical level determines how characters form tokens. A token is a basic component of the source code. Characters belong to one of the five classes of tokens (identifiers, operators, constants, separators, and reserved words). Each class determines the token’s function by the rules of that programming language.
- Phrases – This grammatical level determines how tokens form phrases. Each programming language has its own unique phrasing.
- Context – This contextual level determines the naming conventions (e.g. the variables or objects names refer to) and the validity of types.
Here are the nine major components of computer programming syntax:
Statements
A statement is a syntactic component of an imperative programming language. Using a single line of code, a statement expresses an action to carry out.
Here is an example of a statement written in Perl:
$a = 3;
In this statement, the variable $a is assigned the value 3, a string. Strings are data types used for data values consisting of an ordered sequence of characters.
This type of statement is an assigned statement since a value is assigned to a variable.
Variables
A variable is a value that can change depending on specific conditions or on the information relayed to the program. Generally, a program consists of instructions (which tell the computer what to do) and data (which the program uses when it’s running).
Data consists of variable and constant values. Constant values are also known as fixed values since you can’t change them. Variable values are typically initialized to 0 or another default value since the program’s end-user supplies the actual numbers.
Both variables and constants are often categorized by data type. Examples of data types include a string of text characters with a character limit and integers expressed as decimal numbers.
Operators
An operator is a character or series of characters that usually represent an action or process. Operators tell the compiler or interpreter to perform specific mathematical, relational, or logical operations and produce a final result.
There are three main types of operators in high-level programming languages:
- Mathematical operators – You can use mathematical operators to perform calculations (e.g. addition, subtraction, and multiplication).
- Comparison operators – These allow you to make assignments and comparisons. Comparison operators perform Boolean logic on input data to gain a true or false result. Comparison operators include <, >, >=, <=, ===, and !==.
- Logical operators – These combine relational operators to facilitate more complex decision-making. Logical operators include AND, OR, and NOT.
Keywords
Keywords form part of basic syntax. They’re predefined words that have special meanings to the compiler. This is in contrast to reserved words, which you can’t use as identifiers.
The number of keywords found in a programming language can clearly indicate its complexity. Elixir has about 15 keywords, while Visual Basic has about 217 keywords.
For the list of keywords found in each programming language, check out this list compiled by GitHub.
Identifiers
Identifiers are names given to specific entities, such as variables, constants, type definitions, and structures. While each programming language has rules for assigning descriptive names to entities, identifiers have to abide by that language’s technical limitations. Identifiers also need to follow universal programming best practices.
Data Types
Data types specify which type of value a variable has. Data types also specify what type of mathematical, relational, or logical operations to apply to variables without causing syntax errors. Data types define which operations to perform to create, transform, and utilize the variable in another computation.
Conditionals
Conditionals (also known as conditional statements and expressions) tell a computer what decisions to make when code meets certain conditions. Pre-stated conditions must evaluate to either true or false.
Here’s an example of a conditional Boolean expression:
( money < 7 )
( loop_counter < length_of_loop )
( rent > 700 )
( test_score > 70 && grade_level == 7 )
The information in the parentheses of the if statement is the condition.
A condition needs to evaluate to either true or false. <, >, and == are often used to generate Boolean values.
Functions
Functions are pieces of code that you can use repeatedly instead of writing them out multiple times. They allow programmers to break down or decompose a problem into smaller, more manageable chunks. Each chunk, in turn, performs a specific task.
Once you create a function, you don’t need to document the details of how it works. This allows the programmer to focus on the bigger picture.
Loops
A loop is a sequence of instructions or a block of code that is continuously repeated until it meets a specific condition. A loop’s structure can be virtually divided into two parts: the control statement and the body.
The control statement contains the conditions that the code must meet before executing the body of the loop. For every iteration of the loop, the conditions found in the control statement have to be true. Meanwhile, the body of the loop contains the sequence of logical statements or the block of code to execute multiple times.
Different programming languages have different types of loops. They also apply different rules to determine the actions of loops.
How to Prevent Syntax Errors
As previously mentioned, computers are very exacting when it comes to reading and executing code. While humans can easily spot typos or grammatical errors in a sentence and make the necessary changes, computers don’t possess that level of intelligence.
When you type a command incorrectly or there are errors in the program, the computer does not know how to proceed and will be unable to run the program.
To prevent syntax errors when you’re writing code, consider noting down the syntax for the main statements and function calls. You can use this cheat sheet as a practical reference when you’re writing your code.
How to Fix Syntax Errors
While syntax errors are usually easy to fix once you figure out where they appear in your code, the error messages are rarely helpful. Python’s error messages, for example, include SyntaxError: invalid syntax and SyntaxError: invalid token.
These error messages tell you where in the program the problem is. Sometimes, the error is before the location of the error message, often in the preceding line.
If you’re building a program incrementally, the error is often on the last line you added. On the other hand, if you’re recreating code from a book, you may have copied a line or series of symbols and characters incorrectly. You can spot these errors by comparing every line of code you’ve written to the lines of code in the book.
Note that the book’s code might be wrong or outdated, which requires you to make changes that aren’t recommended by the book.
If the compiler reports errors and you don’t see it, it could be because you and the compiler aren’t looking at the same code. Check your programming environment to verify if the program you’re editing is the same one the compiler is trying to run.
If you’re not sure, try inserting an obvious syntax error at the beginning of the program. Next, run or import the code again. If the compiler doesn’t spot the new error, there is probably something wrong with the way your programming environment is set up.
Semantics vs Syntax in Programming
While we’ve already established how syntax governs the structure of programming languages, we haven’t covered semantics. Simply put, semantics refers to the meaning or interpretation of the code. This includes the symbols, characters, and other pertinent parts of the program.
Semantics is also used to understand the relationship between the syntax and the model of computation. It prioritizes the interpretation of the program so that the programmer can understand it easily or predict the outcome of the program’s execution.
Syntax Examples in Programming
If you’re enrolled in a coding boot camp or taking a course online, you’ll be covering many syntax exercises in your classes.
Here are a couple of simple syntax exercises you could try to gain a better feel for the art and science of coding.
Write Greetings in C
If you’re learning C, try the following example in a free online C compiler:
Change the greeting inside printf() by typing anything in place of Hello Beautiful People! It should print whatever is inside the two double-quotes.
#include <stdio.h>
int main() {
/* printf() function to write Hello, Beautiful People! */
printf( “Hello, Hello Beautiful People!” );
}
Write Greetings in Java
Here is the equivalent program written in Java:
public class HelloBeautifulPeople {
public static void main(String []args) {
/* println() function to write Hello, Hello Beautiful People! */
System.out.println(“Hello, Beautiful People!”);
}
}
In println, change the greeting inside the parentheses (“Hello, Beautiful People!”) to a new greeting. Make sure to use quotation marks to enclose your greeting.
Try the exercise in this free online Java compiler.
Learn Programing at Coding Dojo
Now that you have a basic understanding of how both syntax and semantics operate in programming languages, the next step is to master programming by enrolling in our software development bootcamp at Coding Dojo.
We offer both onsite and online bootcamps, with the curriculum covering everything from the programming basics to a practical overview of the major programming languages—including Python, JavaScript, and SQL. We’ll cover both the front-end and back-end technologies, ensuring that you graduate with a broader skillset and a robust portfolio.
Start your application today and take the first step to launching your career as an A-list software developer!