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Unit ii ppt

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ANJALAI AMMAL MAHALINGAM ENGINEERING COLLEGE

This document provides an overview of C programming basics including character sets, tokens, keywords, variables, data types, and control statements in C language. Some key points include: - The C character set includes lowercase/uppercase letters, digits, special characters, whitespace, and escape sequences. - Tokens in C include operators, special symbols, string constants, identifiers, and keywords. There are 32 reserved keywords that should be in lowercase. - Variables are named locations in memory that hold values. They are declared with a data type and initialized by assigning a value. - C has primary data types like int, float, char, and double. Derived types include arrays, pointers, unions, structures,

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Unit ii ppt
UNIT-II C PROGRAMMING BASICS
PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
CHARACTER SET C CHARACTER SET Execution Character Set Source Character Set DigitsAlphabets Special Character White Space Character Space Escape Sequence PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
A Character denotes an alphabet, digit or a special character. Lowercase Letters – A,B,C….. Z Uppercase Letters - a,b,c…… z Digits – 0,1,2,3,…7,8,9 + Plus Sign - Minus Sign , Comma * Asterisk / Slash = Equal to @ At Symbol < Less Than : Colon ; Semicolon PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
It will work at the execution time only and it cannot be printed. It always represented by a backslash() followed by a character. PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
 The smallest individual units of a c program are known as tokens  It can be categorized into following ways C tokens operators Special symbolstringconstantsIdentifiersKeywords PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
 Keyword is a reserved keyword that has a particular meaning  It should be in lower case  There are 32 keywords in c language S. NO keyword S. NO keyword S.NO keyword S. NO keyword keyword 1 auto 8 do 15 goto 22 signed 29.unsigned 2 break 9 double 16 if 23 sizeof 30.void 3 case 10 else 17 int 24 static 31.volatile 4 char 11 enum 18 long 25 struct 32.while 5 const 12 extern 19 register 26 switch 6 continue 13 float 20 return 27 typedef 7 default 14 for 21 short 28 union PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
 It can be a variable name and function name etc.  Maximum length of an identifier is 31  Special character are not allowed except(_). Valid invalid nithiya Nithya# NITHIYA Nith ya ->blank space Nithya3 Auto Nithya 3nithya PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
10 -356 4600.5 -0.963 ‘A’ ‘*’ “A” “CSC” PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
Variables are named locations in memory that are used to hold a value that may be modified by the program. K5.ico ANIMATAY006.ICO The syntax for declaring a variable is Data type Variablename; Valid Examples : CSC avg_val m1 Chennai Anu mark_1 PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
RULES for framing a variable : The first character in the Variable name must be an alphabet Alphabets can be followed by a number of digits or underscores No commas or Blank spaces are allowed within a variable name No Special character other than Underscore(_) can be used in a variable name. The variable name should not be a keyword Variable names are case sensitive It should not be of length more than 31 characters PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
INTIALIZING VARIABLE Assigning some value to the variable is known as intialization SYNTAX: Data type variable name=value; Example Int a=10; SCOPE OF VARIABLE 1.Local variable 2.Global variable PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
Scope of variable definition example Local variable Declared inside the block main() { Int a=8; // local variable } Global variable Declared before the main function Int a=8; Main() { //no of statement } PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
C data types Empty data type User defined data type Derived or secondary data type Primary data type PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG PRIMARY DATA TYPES int float chardouble 1.PRIMARY DATA TYPES
S.N O Data Type Explanation Size(bytes) CONTRO L STRING RANGE SYNTAX EXAMPLE 1 int It store numeric values without decimal point Example:9,10,23 2 bytes %d or %i -32,768 to +32,767 int Variable_na me; int roll_no; 2 float It store the numeric values with decimal point Example:3.12,47.098 4 bytes %f or %g 3.4E-38 to 3.4E+38 Float Variable_na me; float a; 3 double It store the big number of decimal point Example:2.13455 8 bytes %if 1.7E-308 to 1.7E+308 Double Variable name; double b; 4 char It store the single character Example:’a’,’9’ 1 bytes %c -128 to +127 Char Variable name; char a=“nithiya”; PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
1.Array An array is a collection of variable of same data type SYNTAX: Datatype array_name[array size]; Example: int a[10]; 2.Structures it stores the multiple values of same or different data type under a single name Syntax: Struct <struct name> { Member 1;member 2;}; DERIVED DATA TYPE array pointersunionsstructures
EXAMPLE: Struct Student { Char name[10]; Int roll_no; }; 3.UNION A union is store the multiple values of same or different data type SYNTAX: union <union name> { Member 1; member 2; } EXAMPLE: Union student { Char name[25]; }; PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
4.POINTERS A pointer is holds the memory address of another variable SYNTAX: Data type *variable name EXAMPLE : int *a EMPTY DATA TYPE i)Void its represents an empty value PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
1.Type Definition Example: Typedef int age; age male,female 2.Enumerated Datatype Example : enum mon{jan,feb,mar,apr,may,jun,jul,aug,sep,oct,nov,dec }; PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG USER DEFINED DATA TYPE
Control statement conditional unconditional selective looping Nested if else Simple if If else If-else if ladder Switch case while do while for goto break continue PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
 A program is a sequence of one or more instructions  The condition will check whether the particular condition are true (or) not.  1.SIMPLE IF STATEMENT  If the condition is true the set of statements are executed  SYNTAX  if(condition) { Statement 1; } PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
To find the given no is even or odd #include<stdio.h> #include<conio.h> main() { int no; clrscr(); printf(“n Enter the number”); scanf(“%d”,&no); if(no%2==0) { printf(The given no is even”); }} Output Enter the number 24 The given no is even PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
2.if else statement It is a two way decision making statement SYNTAX: if(condition) { Statement 1; } else { false statement; } #include<stdio.h> #include<conio.h> main() { int no; clrscr(); printf(“n Enter the number”); scanf(“%d”,&no); if(no%2==0) { printf(The given no is even”); } else { Printf(“The given no is odd”); } #include<stdio.h> #include<conio.h> main() { int no; clrscr(); printf(“n Enter the number”); scanf(“%d”,&no); if(no%2==0) { printf(The given no is even”); } else { Printf(“The given no is odd”); } Output Enter the number 25 The given no is odd PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
 The number of logical conditions is checked for executing various statements  SYNTAX  if(condition 1)  {  True statement 1;  }  else  {  if(condition 2)  {  True statement 2;  }  else  {  False statement }} #include<stdio.h> #include<conio.h> Main() { int a,b,c; clrscr(); printf(“Enter a,b,c”); scanf(“%d%d%d”,&a,&b,&c); if((a>b)&&(a>c)) { printf(“A is greater”); } else { If(b>c) { printf(“B is greater”); } else { printf(“C is greater”); }}} Output Enter the values of a,b,c 4 2 3 A is greater
Nested if-else can be chained with one another Syntax: if(condition 1) { Statement 1; } else if(condition 2); { Statement 2; } else if(condition 3) { statement; } else { Final statement } #include<stdio.h> #include<conio.h> Main() { int a,b,c; clrscr(); printf(“Enter a,b,c”); scanf(“%d%d%d”,&a,&b,&c); if(a>b) { If(a>c) { printf(“A is greater”); } else { printf(“C is greater”); } } else if(b>c) { printf(“B is greater”); } else { printf(“C is greater”); }} Output Enter the values of a,b,c 4 2 3 A is greater PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
 If the value matches with case constant, this particular case statement is executed. if not default is executed.  SYNTAX:  Switch (variable)  {  Case constant 1:  statement 1;  Break;  Case constant 2:  Statement 2;  Break;  ..  ..  default:  Default statement;  } #include<stdio.h> #include<conio.h> Main() { int a=10,b=5; char symbol; clrscr(); printf(“Enter the symbol”); scanf(“%c”,&symbol); switch(symbol) { case’+’: result=a+b; break; case’-’: result=a-b; break; case’*’: Result=a*b; Break; Case’/’: Result=a/b; break; case’%’: Result=a%b; break; } Default: Printf(“invalid symbol”); } Printf(“the result is %d”,result); } Output Enter the symbol:+ The result is 15 Enter the symbol:% The result is 0 PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG

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Unit ii ppt

  • 4. CHARACTER SET C CHARACTER SET Execution Character Set Source Character Set DigitsAlphabets Special Character White Space Character Space Escape Sequence PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 5. A Character denotes an alphabet, digit or a special character. Lowercase Letters – A,B,C….. Z Uppercase Letters - a,b,c…… z Digits – 0,1,2,3,…7,8,9 + Plus Sign - Minus Sign , Comma * Asterisk / Slash = Equal to @ At Symbol < Less Than : Colon ; Semicolon PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 6. It will work at the execution time only and it cannot be printed. It always represented by a backslash() followed by a character. PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 7.  The smallest individual units of a c program are known as tokens  It can be categorized into following ways C tokens operators Special symbolstringconstantsIdentifiersKeywords PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 8.  Keyword is a reserved keyword that has a particular meaning  It should be in lower case  There are 32 keywords in c language S. NO keyword S. NO keyword S.NO keyword S. NO keyword keyword 1 auto 8 do 15 goto 22 signed 29.unsigned 2 break 9 double 16 if 23 sizeof 30.void 3 case 10 else 17 int 24 static 31.volatile 4 char 11 enum 18 long 25 struct 32.while 5 const 12 extern 19 register 26 switch 6 continue 13 float 20 return 27 typedef 7 default 14 for 21 short 28 union PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 9.  It can be a variable name and function name etc.  Maximum length of an identifier is 31  Special character are not allowed except(_). Valid invalid nithiya Nithya# NITHIYA Nith ya ->blank space Nithya3 Auto Nithya 3nithya PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 11. Variables are named locations in memory that are used to hold a value that may be modified by the program. K5.ico ANIMATAY006.ICO The syntax for declaring a variable is Data type Variablename; Valid Examples : CSC avg_val m1 Chennai Anu mark_1 PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 12. RULES for framing a variable : The first character in the Variable name must be an alphabet Alphabets can be followed by a number of digits or underscores No commas or Blank spaces are allowed within a variable name No Special character other than Underscore(_) can be used in a variable name. The variable name should not be a keyword Variable names are case sensitive It should not be of length more than 31 characters PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 13. INTIALIZING VARIABLE Assigning some value to the variable is known as intialization SYNTAX: Data type variable name=value; Example Int a=10; SCOPE OF VARIABLE 1.Local variable 2.Global variable PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 14. Scope of variable definition example Local variable Declared inside the block main() { Int a=8; // local variable } Global variable Declared before the main function Int a=8; Main() { //no of statement } PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 15. C data types Empty data type User defined data type Derived or secondary data type Primary data type PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG PRIMARY DATA TYPES int float chardouble 1.PRIMARY DATA TYPES
  • 16. S.N O Data Type Explanation Size(bytes) CONTRO L STRING RANGE SYNTAX EXAMPLE 1 int It store numeric values without decimal point Example:9,10,23 2 bytes %d or %i -32,768 to +32,767 int Variable_na me; int roll_no; 2 float It store the numeric values with decimal point Example:3.12,47.098 4 bytes %f or %g 3.4E-38 to 3.4E+38 Float Variable_na me; float a; 3 double It store the big number of decimal point Example:2.13455 8 bytes %if 1.7E-308 to 1.7E+308 Double Variable name; double b; 4 char It store the single character Example:’a’,’9’ 1 bytes %c -128 to +127 Char Variable name; char a=“nithiya”; PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 17. 1.Array An array is a collection of variable of same data type SYNTAX: Datatype array_name[array size]; Example: int a[10]; 2.Structures it stores the multiple values of same or different data type under a single name Syntax: Struct <struct name> { Member 1;member 2;}; DERIVED DATA TYPE array pointersunionsstructures
  • 18. EXAMPLE: Struct Student { Char name[10]; Int roll_no; }; 3.UNION A union is store the multiple values of same or different data type SYNTAX: union <union name> { Member 1; member 2; } EXAMPLE: Union student { Char name[25]; }; PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 19. 4.POINTERS A pointer is holds the memory address of another variable SYNTAX: Data type *variable name EXAMPLE : int *a EMPTY DATA TYPE i)Void its represents an empty value PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 20. 1.Type Definition Example: Typedef int age; age male,female 2.Enumerated Datatype Example : enum mon{jan,feb,mar,apr,may,jun,jul,aug,sep,oct,nov,dec }; PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG USER DEFINED DATA TYPE
  • 21. Control statement conditional unconditional selective looping Nested if else Simple if If else If-else if ladder Switch case while do while for goto break continue PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 22.  A program is a sequence of one or more instructions  The condition will check whether the particular condition are true (or) not.  1.SIMPLE IF STATEMENT  If the condition is true the set of statements are executed  SYNTAX  if(condition) { Statement 1; } PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 23. To find the given no is even or odd #include<stdio.h> #include<conio.h> main() { int no; clrscr(); printf(“n Enter the number”); scanf(“%d”,&no); if(no%2==0) { printf(The given no is even”); }} Output Enter the number 24 The given no is even PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 24. 2.if else statement It is a two way decision making statement SYNTAX: if(condition) { Statement 1; } else { false statement; } #include<stdio.h> #include<conio.h> main() { int no; clrscr(); printf(“n Enter the number”); scanf(“%d”,&no); if(no%2==0) { printf(The given no is even”); } else { Printf(“The given no is odd”); } #include<stdio.h> #include<conio.h> main() { int no; clrscr(); printf(“n Enter the number”); scanf(“%d”,&no); if(no%2==0) { printf(The given no is even”); } else { Printf(“The given no is odd”); } Output Enter the number 25 The given no is odd PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 25.  The number of logical conditions is checked for executing various statements  SYNTAX  if(condition 1)  {  True statement 1;  }  else  {  if(condition 2)  {  True statement 2;  }  else  {  False statement }} #include<stdio.h> #include<conio.h> Main() { int a,b,c; clrscr(); printf(“Enter a,b,c”); scanf(“%d%d%d”,&a,&b,&c); if((a>b)&&(a>c)) { printf(“A is greater”); } else { If(b>c) { printf(“B is greater”); } else { printf(“C is greater”); }}} Output Enter the values of a,b,c 4 2 3 A is greater
  • 26. Nested if-else can be chained with one another Syntax: if(condition 1) { Statement 1; } else if(condition 2); { Statement 2; } else if(condition 3) { statement; } else { Final statement } #include<stdio.h> #include<conio.h> Main() { int a,b,c; clrscr(); printf(“Enter a,b,c”); scanf(“%d%d%d”,&a,&b,&c); if(a>b) { If(a>c) { printf(“A is greater”); } else { printf(“C is greater”); } } else if(b>c) { printf(“B is greater”); } else { printf(“C is greater”); }} Output Enter the values of a,b,c 4 2 3 A is greater PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG
  • 27.  If the value matches with case constant, this particular case statement is executed. if not default is executed.  SYNTAX:  Switch (variable)  {  Case constant 1:  statement 1;  Break;  Case constant 2:  Statement 2;  Break;  ..  ..  default:  Default statement;  } #include<stdio.h> #include<conio.h> Main() { int a=10,b=5; char symbol; clrscr(); printf(“Enter the symbol”); scanf(“%c”,&symbol); switch(symbol) { case’+’: result=a+b; break; case’-’: result=a-b; break; case’*’: Result=a*b; Break; Case’/’: Result=a/b; break; case’%’: Result=a%b; break; } Default: Printf(“invalid symbol”); } Printf(“the result is %d”,result); } Output Enter the symbol:+ The result is 15 Enter the symbol:% The result is 0 PREPARED BY K,NITHIYA AP/IT ANNAI CLG OF ENGG