Format specifier & Token in C Language

Format specifier:

Format specifier will indicates that what type of data we requires to print on console


Int - %d

Float-%f               Format specifiers




Smallest unit in programming or an individual unit in programming are called “Token”

A C program is a collection of tokens

Tokens can be keyword, operator, and separator, constant and any other identifier.

When we’re working with the token, we can’t break the token or we can’t split the token but s/w the tokens. We can give ‘n’ no of spaces, tabs and new lines

Eg: void main(){Pri ntf(“welcome”);


o/p: error

Void main{Printf(“welcome”);




Printf-> to print anything on to the console

Printf(“Hello”); Hello

Printf(“****hello”); ***hello;

Print(“%dwelcome%d”__ 10,20); error

Function call mission(,)

Printf(“%d welcome %d”,10,20); error

Function call missing

Printf(“%dwelcome %d”,10,20)  error

Statement mission(;)

Printf(“@@@welcome###”); @@@welcome###

Printf(“%d welcome %d”,10,20); 10 welcome20

Printf(“%d%d%d,10,20,30”); 102030

Printf(“%d %d %d”, 10,20,30); 10 20 30

Printf(“%d %d %d”,100,200,300); 100,200,300

Printf(“2+3=%d”,2+3); 2+3=5


Within the double quotes except format specifiers and special characters rest of all content will consider as characters only.

Printf(“%d*%d=%d”,2,5); 2*5=10

Printf(“%d%d  %d”,100,200); 100,200 gr/junk    gr=garbage


  • In printf() statement, when we are passing an additional format specifier which doesn’t contains correspondent value, then it prints some unknown or undefined value called garbage / junk
  • Printf(“%d %d”,100,200,300); 100,200


In printf() statement, when we are passing an additional value which doesn’t contains correspondent format specifiers, then that value will be ignored

  • Printf(“Total salary=%d”, 25,000);

Total salary=25

  • Printf(“total salary=%d”, 25000);

Total salary=25000

  • Printf(“%d%d”,2<5,!5!=5); 1 1

Void main()





o/p= Error undefined symbol ‘a’


void  main()


Int a;     // declaration

a=35; // Assigning



o/p:  a=35




It is a pre-defined f’n, by using this f’n we can print the data on console.

  • The scientific name of the monitor is called “console”
  • When we are working with the printf, it can take any no.of arguments but 1st argument must be within the double codes and every argument should be separated with ‘,’
  • Within the double codes whatever we pass it pins assist i.e. if any format specifiers are there then copy that type of values.