CONSTANTS IN C++…
CONSTANTS IN C++
Constant என்பது program execution நடக்கும் போது அதன் value change ஆகாமல் இருக்கும் fixed value. Simple definition: A constant is a fixed value that does not change during program execution.
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11 programs 9 MCQs v2
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Definition
Constant என்பது program execution நடக்கும் போது அதன் value change ஆகாமல் இ……
Explanation
Example
const int MAX = 100; இங்கு: MAX → Constant identifier 10……
Simple Explanation
Variable என்றால் value change ஆகலாம். int age = 20; age = 21; இங்கு age value: 20 → 21 என்று change ஆகிறது……
Real Life Example
Real-life example
Mathematics-ல்: π = 3.14159... π-ன் value fixed. அத……
Explanation
Why constants are needed
Program-ல் சில values change ஆகக்கூடாது. PI Number of days in a week Maximum marks Tax rate Conversion value ……
Explanation
return 0; }…
Explanation
const int MAX_MARK = 100; const C++ keyword. Compiler-க்கு: இந்த variable-ன் value later change செய்யக……
Explanation
What happens if we change it?
const int MAX = 100; MAX = 200; இது invalid. Comp……
Comparison
Variable vs constant
Variable int x = 10; x = 20; V……
Explanation
Types of constant values / literals
C++-ல் fixed values பல types-ல் இருக்கலாம். Main types: Int……
INTEGER CONSTANT
Explanation
Decimal point இல்லாத whole number values. Examples: 10 100 ……
Real Life Example
Integer constant examples
const int DAYS = 7; const int MONTHS = 1……
FLOATING-POINT CONSTANT
Real Life Example
Decimal point கொண்ட numbers. ……
Explanation
Example
const float PI = 3.14;…
3.14 → Floating-point literal.
Explanation
Double constant
const double PI = 3.14159265; Her……
CHARACTER CONSTANT
Explanation
Single character-ஐ single quotation marks ' ' குள் எழு……
Important
Character: 'A' Single quotes. S……
STRING LITERAL
Important
Multiple characters-ஐ double quotation mar……
Explanation
Example
string name = "Ravi"; "Ravi" → String lite……
BOOLEAN LITERALS
Explanation
C++-ல் Boolean literals இரண்டு: tru……
Comparison
Literal vs const constant
இந்த concept மிகவும் important. Consider: const int MAX = 100; இதில்: const → Keyword MAX → Identifier 100 → ……
Real Life Example
Example
int x = 50; 50 ஒரு integer literal. ஆனால் x constant அல்ல. Beca……
Explanation
Constant initialization
Normally const variable declare செய்யும்போதே initialize செய்வது வேண்டும். Correct: co……
Flow
Declare constant | v const int MAX = 100; | v Value ……
Program
Program 2
Explanation
double radius = 5; double are……
Explanation
return 0; }…
approximately.…
Explanation
const double PI = 3.14159; PI constant. double ra……
Formula
Area = πr² So: 3.14159 × 5 × ……
Explanation
Program
const int MAX = 100; int mark……
Program
Step 1
Explanation
Fixed. Step 2:…
Explanation
Variable. Step 3: Program pri……
Explanation
compiler rejects it.…
Explanation
Symbolic constants
Older C/C++ code-ல் #define மூலம் symbolic constants உருவாக்கப்படலாம்……
Comparison
Const vs #define
Modern C++-ல் பொதுவாக typed c……
Explanation
Example
const double PI = 3.14; compa……
Comparison
Difference
Important
Constexpr - important advanced point
Modern C++-ல்: constexpr int SIZE = 10; constexpr என்பது ……
Explanation
Example
constexpr int DAYS = 7; For basics: const → value cannot be modified through that const obj……
Explanation
Naming convention
Constants-க்கு uppercase names பயன்படுத்துவது common convention. const int MAX_SIZE = 100; const ……
Common Mistake
Common error 1
const int MAX = 100; MAX = 200;……
Common Mistake
Common error 2
const int MAX; Local const object-க்கு in……
Common Mistake
Common error 3
Character மற்றும் string confuse செய்வது. Wr……
Common Mistake
Common error 4
Constant name uppercase-ல் இருக்க வேண்டும் என்பது compulsory ……
Important
Important difference
Consider: const int x = 10; இதை token-wise பார்க்கலாம்: const → Keyword int → Keyword / type specifie……
Explanation
Example
const int A = 10; const int B……
Explanation
C-ன் value initialization முட……
Important
const என்பது ஒரு type qualifi……
Explanation
Example
const int x = 10; இதில் const compi……
Remember
CONST = CONSTANT = CANNOT CHANGE V……
Explanation
Example
int x = 10; Change possible. ……
TRB Point
Question
What is a constant in C++? Answer: A constant is a fixed v……
MCQ
const int x = 10; Which state……
Interview Point
Difference between constant and literal? Consider: const int MAX = 100; MAX → named constant ……
MCQ
Which keyword is commonly use……
MCQ
Which is correct?…
MCQ
In: const int MAX = 100; 100 ……
MCQ
In: const int MAX = 100; MAX ……
MCQ
Which is a floating-point lit……
MCQ
Which is a character literal?…
MCQ
Which are Boolean literals in……
MCQ
What happens here? const int ……
Practice
Identify each part: const double RATE = 5.5; Answer: cons……
5.5 → Floating-point literal
; → Punctuator…
Practice
Practice 2
Which can be changed? int x = 10; const int y = 20; Answer:……
Summary
Constant A fixed value that d……
Explanation
Syntax
const data_type name = value; const int MAX = 100; Breakdown: const → K……
3.14 → Floating point
'A' → Character "Hello" → String true → Boolean Most important exam difference: int x = 10; x ……
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