{"id":2820,"date":"2025-06-07T14:51:00","date_gmt":"2025-06-07T14:51:00","guid":{"rendered":"https:\/\/diznr.com\/?p=2820"},"modified":"2025-06-07T14:51:00","modified_gmt":"2025-06-07T14:51:00","slug":"lexical-analysis-in-simple-words-token-generation-blank-space-symbol-table-error-lexical","status":"publish","type":"post","link":"https:\/\/www.reilsolar.com\/pdf\/lexical-analysis-in-simple-words-token-generation-blank-space-symbol-table-error-lexical\/","title":{"rendered":"Lexical Analysis in simple words – token generation, blank space, symbol table, lexical error"},"content":{"rendered":"

Lexical Analysis in simple words – token generation, blank space, symbol table, lexical error<\/p>\n

[fvplayer id=”129″]<\/p>\n

Lexical Analysis in Simple Words<\/strong><\/h3>\n

Lexical Analysis is the first phase of a compiler<\/strong> that breaks down the source code into smaller meaningful units<\/strong> called tokens<\/strong>. This process is done by a program called the Lexical Analyzer (Lexer).<\/strong><\/p>\n

\u00a0How Lexical Analysis Works?<\/strong><\/h3>\n

\u00a0The source code is read character by character<\/strong>.
\u00a0Meaningful groups of characters are converted into tokens<\/strong>.
\u00a0Unnecessary characters like spaces, tabs, and comments<\/strong> are removed.
\u00a0A symbol table<\/strong> is created to store identifiers and keywords.
\u00a0If an unknown symbol is found, a lexical error<\/strong> is reported.<\/p>\n

\u00a0Example of Token Generation<\/strong><\/h3>\n

Input Code:<\/strong><\/p>\n

\n
int<\/span> x = 10<\/span>;
\n<\/code><\/div>\n<\/div>\n

Lexical Analyzer Output (Tokens):<\/strong><\/p>\n

\n
Keyword: int <\/span>
\nIdentifier: x <\/span>
\nOperator: = <\/span>
\nNumber: 10 <\/span>
\nSymbol: ;<\/span>
\n<\/code><\/div>\n<\/div>\n

Each part of the code is classified into a specific token type<\/strong>.<\/p>\n

\u00a0Handling Blank Spaces & Comments<\/strong><\/h3>\n

Whitespace (spaces, tabs, new lines)<\/strong> is ignored<\/strong> by the lexical analyzer.
Comments (\/\/<\/code>, \/* ... *\/<\/code>)<\/strong> are removed, as they don\u2019t affect program execution.<\/p>\n

Example:<\/strong><\/p>\n

\n
int<\/span> a = 5<\/span>; \/\/ This is a comment<\/span>
\n<\/code><\/div>\n<\/div>\n

\u00a0The lexer ignores<\/strong> \"\/\/ This is a comment\"<\/code> and processes only:<\/p>\n

\n
\n
\n
<\/div>\n<\/div>\n<\/div>\n
Keyword: int <\/span>
\nIdentifier: a <\/span>
\nOperator: = <\/span>
\nNumber: 5 <\/span>
\nSymbol: ;<\/span>
\n<\/code><\/div>\n<\/div>\n

\u00a0Symbol Table<\/strong><\/h3>\n

\u00a0A symbol table<\/strong> stores identifiers (variable names, function names) and their attributes like data type, memory location, scope, etc.<\/strong>
\u00a0It helps the compiler track variables<\/strong> efficiently.<\/p>\n

Example Symbol Table:<\/strong><\/p>\n

\n\n\n\n\n\n\n
Identifier<\/th>\nType<\/th>\nMemory Location<\/th>\n<\/tr>\n<\/thead>\n
x<\/td>\nint<\/td>\n1001<\/td>\n<\/tr>\n
y<\/td>\nfloat<\/td>\n1002<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

\u00a0Lexical Errors<\/strong><\/h3>\n

Errors occur when the lexer finds an unknown or invalid character<\/strong>.<\/p>\n

Example:<\/strong><\/p>\n

\n
int<\/span> @x = 10<\/span>;
\n<\/code><\/div>\n<\/div>\n

Lexical Error:<\/strong> “Unexpected character ‘@’ found.”<\/strong><\/p>\n

\u00a0Summary<\/strong><\/h3>\n

Lexical Analysis<\/strong> breaks code into tokens<\/strong>.
Blank spaces & comments<\/strong> are ignored.
\u00a0A symbol table<\/strong> stores variable names and types.
Lexical errors<\/strong> occur due to unknown characters.<\/p>\n

Would you like a step-by-step breakdown<\/strong> of a real Lexical Analysis process?<\/p>\n

Lexical Analysis in simple words – token generation, blank space, symbol table, lexical error<\/a><\/h3>\n

LEXICAL ANALYSIS Structure of compiler \u2013 Functions and …<\/a><\/h3>\n

Lexical Analysis – Compiler Construction<\/a><\/h3>\n

compiler design lecture notes<\/a><\/h3>\n

Chapter 3 Lexical Analysis<\/a><\/h3>\n

CS 335: Lexical Analysis<\/a><\/h3>\n

Here is a simple explanation of Lexical Analysis<\/strong> and its key components, written in easy language (suitable for beginners or non-technical readers):<\/p>\n

\n

\ud83d\udcd8 Lexical Analysis in Simple Words<\/strong><\/h2>\n

Lexical Analysis<\/strong> is the first step of a compiler<\/strong>.
It reads the code written by a programmer and breaks it into small parts called tokens<\/strong>.<\/p>\n

\n

\ud83d\udd39 1. What is a Token?<\/strong><\/h3>\n

A token<\/strong> is a small, meaningful unit in a programming language.
Think of it like words in a sentence.<\/p>\n

\ud83e\udde0 Example:<\/h4>\n
\n
c<\/div>\n
\n
\n