Difference between revisions of "PERL/C2/while-do-while-loops/English-timed"

|Welcome to the spoken tutorial on '''while and do-while''' loops in '''Perl'''.

|* '''while''' loop in '''Perl'''  

|* '''do-while''' loop in '''Perl '''.

   

| I am using '''Ubuntu Linux 12.04''' operating system and '''Perl 5.14.2'''.

| You should have basic knowledge of "variables" and "comments" in ''' Perl.'''

|| close curly bracket.  

| Now Type the following code:  

|'''print''' space double quote '''Value of i''' colon ''' dollar i slash n'''  double quote complete semicolon

|press '''Enter '''.

| press '''Enter'''  and  

 

|close the curly bracket.  

| Now again, the loop condition ''' $i<=4''' will be evaluated.  

| 04:02

|piece of code to be executed while the condition is true  

|'''print''' space double quote '''Value of i colon space dollar i slash n''' close double quote semicolon  

|Press '''Enter '''

|'''dollar i plus plus semicolon'''

| 05:52

| press '''enter '''

| close curly bracket  

|space '''while space''' open bracket '''dollar i less than or equal to four '''

| close bracket semicolon  

|First time, the '''do-while''' loop will print the output as ''' 'Value of i colon 0' ''' on the terminal without checking for condition

|''' $i++ ''' will increment the value of variable i by one each time loop gets executed.  

| Second time, the condition '''$i''' less than or equal to 4 will be checked.  

| If the condition is true, the loop will get executed again.  

|In our case, second time the output displayed on terminal will be ''' 'Value of i colon 1' '''.

|  The loop will get executed till the condition becomes false that is when variable i becomes 5.  

| Press '''ctrl+s''' to '''save''' the file.  

| The following line will be displayed on the terminal

| '''doWhileLoop.pl syntax OK '''

|As there are no compilation or syntax errors, we will now execute the '''Perl''' script.  

|Type '''perl doWhileLoop dot pl'''

|and press '''Enter'''

| Open the Terminal, type -

| and press '''Enter'''

| We have declared a variable '''count''' and initialized it to zero  

|The condition is not true. So the loop will exit.  

|Now, press '''ctrl+s''' to save the file.  

|Now, switch to terminal and type the following to check for any compilation or syntax errors  

|As there are no compilation or syntax errors, let us execute the '''Perl''' script.

|By Typing '''perl loop dot pl'''

|Here we can see, there is no output message displaying ''' 'I am in while loop' '''

|This message was what we printed inside the while loop.  

|This implies that,

|whereas '''while''' loop does not get executed even once when the condition specified is false.  

|In this tutorial, we have learnt -

|Here is assignment for you -  

|by using '''while''' loop and '''do-while''' loops  

|Watch the video available at the following link  

|It summaries the Spoken Tutorial project

|If you do not have good bandwidth, you can download and watch it

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| Hope you enjoyed this Perl tutorial.  

|This is Amol Brahmankar signing off.