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Difference between Syntax and Semantics

Here you will learn about difference between Syntax and Semantics with example.

The both terms might seem the same things but they are not, they are just interrelated concepts, which even exist as individuals.

What is Syntax?

When we talk about a language (not just a programming language), let’s say English (most common one), there are certain rules of grammar we have to follow if we want to practice this language in the real world. These rules actually define the structure of our sentence.

A Simple rule: Noun + Verb + object

To make sense and let others understand what we want to convey in certain language, we need these rules. They are the grammar of a language that the user must follow.

Same is in programming, if we talk about any language like C, C++, Java, etc there are certain rules that we follow when coding to make the compiler understand what we want to convey.

Some of these rules are:

  1. Command terminates with a semi colon.
  2. Code block starts with a opening curly brace “{“ and ends with a closing curly brace “}”.
  3. for loop has three statements inside round brackets“()”, first one is initialise, second one is condition and third is variable update.

So these actually form a structure to write something that is correct and agrees with the grammar of a language.

This grammar of a language is called Syntax of that language.

What is Semantics?

Semantics, on the other hand, deals with the logical part of a sentence/statement. Let’s say the following English sentence:

Dog fly aeroplane.

This sentence is correct on the part of the syntax of the English Grammar

A Simple rule: Noun + Verb + object

But it’s not logically correct (if are not being sarcastic).

This logical meaning of a sentence that defines its validity is what we call Semantics of that sentence.

Semantics deals with the meaning of a sentence. In programming, if call a function that can only work on two values of a ‘char’ variable.

func(char c){
        if(c == 'y'){
                //DO SOMETHING
        }
        else if(c == 'n'){
                //DO ANOTHERTHING
        }
}

And we call this function with some other value:

func(‘a’);

This statement is perfect with the syntax aspect but is logically wrong i.e., semantically wrong.

Lets know about syntax vs semantics in tabular form.

Difference between Syntax and Semantics

Syntax Semantics
The grammar of a language is called Syntax. Semantics deals with the meaning of a sentence.
Syntax errors can be caught at compilation time and are easy to track. Semantics errors are hard to find. They are mostly encountered at runtime, or when the results do not match with the expectations.

So this was the major difference between semantics and syntax of a language, or even in general to anything.

The post Difference between Syntax and Semantics appeared first on The Crazy Programmer.



from The Crazy Programmer https://www.thecrazyprogrammer.com/2018/05/difference-between-syntax-and-semantics.html
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