 section .data
 welcome:   db 'Hello! This app will determine if your number is even or odd. Please enter a number :',0xa
 welcomelen equ $-welcome
 Res:       db 'You entered:'
 reslen     equ $-Res
 this:      db 0xa,'This number is '
 thislen    equ $-this
 even:      db 'Even',0xa
 evenlen    equ $-even
 odd:       db 'Odd'
 oddlen     equ $ -odd
 

section .bss
 input resb 5
 
section .text
	
	global _start
_start:	
	;Print welcome message
	mov eax,4
	mov ebx,1
	mov ecx,welcome
	mov edx,welcomelen
  int 80h
  
  ;get user input
  mov eax,3
  mov ebx,0
  mov ecx,input
  mov edx,5
  int 80h
  
  ;print 'You entered'
 
  mov eax,4
	mov ebx,1
	mov ecx,Res
	mov edx,reslen
  int 80h
  
  ;print user number
  mov eax,4
	mov ebx,1
	mov ecx,input
	mov edx,5
  int 80h
  
  ;print 'this number is'
  mov eax,4
	mov ebx,1
	mov ecx,this
	mov edx,thislen
  int 80h


  
  ;determine whether input is odd/prints 'odd'. If not executes procedure evnn to print 'even'
  
   mov   ax, [input]          ;getting 8 in the ax 
   and   ax, 1              ;and ax with 1, checks if least bit is 1
   jz    evnn               ; executed 'even procedure if and returns 0'
   mov   eax, 4             ;system call number (sys_write)
   mov   ebx, 1             ;file descriptor (stdout)
   mov   ecx,odd      ;message to write
   mov   edx,oddlen         ;length of message
   int   0x80               ;call kernel
   jmp   outprog
   
   
   
evnn:   
  
   mov   ah,  09h
   mov   eax, 4             ;system call number (sys_write)
   mov   ebx, 1             ;file descriptor (stdout)
   mov   ecx, even      ;message to write
   mov   edx, evenlen          ;length of message
   int   0x80               ;call kernel
  
  ;successful exit
  
outprog:
  mov eax,1
  mov ebx,0
  int 80h

created 3 years ago

Assembly Online Compiler

Write, Run & Share Assembly code online using OneCompiler's Assembly online compiler for free. It's one of the robust, feature-rich online compilers for Assembly language. Getting started with the OneCompiler's Assembly compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as Assembly and start coding.

About Assembly

Assembly language(asm) is a low-level programming language, where the language instructions will be more similar to machine code instructions.

Every assembler may have it's own assembly language designed for a specific computers or an operating system.

Assembly language requires less execution time and memory. It is more helful for direct hardware manipulation, real-time critical applications. It is used in device drivers, low-level embedded systems etc.

Syntax help

Assembly language usually consists of three sections,

Data section

To initialize variables and constants, buffer size these values doesn't change at runtime.
bss section

To declare variables
text section

_start specifies the starting of this section where the actually code is written.

Variables

There are various define directives to allocate space for variables for both initialized and uninitialized data.

1. To allocate storage space to Initialized data

Syntax

variable-name    define-directive    initial-value

Define Directive	Description	Allocated Space
DB	Define Byte	1 byte
DW	Define Word	2 bytes
DD	Define Doubleword	4 bytes
DQ	Define Quadword	8 bytes
DT	Define Ten Bytes	10 bytes

2. To allocate storage space to un-initialized data

Define Directive	Description
RESB	Reserve a Byte
RESW	Reserve a Word
RESD	Reserve a Doubleword
RESQ	Reserve a Quadword
REST	Reserve a Ten Bytes

Constants

Constants can be defined using

1. equ

To define numeric constants

CONSTANT_NAME EQU regular-exp or value

2. %assign

To define numeric constants.

%assign constant_name value

3. %define

To define numeric or string constants.

%define constant_name value

Loops

Loops are used to iterate a set of statements for a specific number of times.

mov ECX,n
L1:
;<loop body>
loop L1

where n specifies the no of times loops should iterate.

Procedures

Procedure is a sub-routine which contains set of statements. Usually procedures are written when multiple calls are required to same set of statements which increases re-usuability and modularity.

procedure_name:
   ;procedure body
   ret