The for loop in C++

<div class="MsoNormal"> <span style="font-size: 16pt; text-align: justify;">The for loop is the easiest loop in C++ to understand. All elements of this loop are in one place contrary to those remaining two (while, do-while) whose elements are scattered in the program.</span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">For loop executes a section of for a certain number of times.<o:p></o:p></span></div> <div class="MsoNormal"> <b><span style="font-size: 24.0pt; line-height: 107%;"><br /></span></b></div> <div class="MsoNormal"> <b><span style="font-size: 24.0pt; line-height: 107%;">Syntax <o:p></o:p></span></b></div> <div class="MsoNormal"> <b><span style="font-size: 24.0pt; line-height: 107%;"><br /></span></b></div> <div class="MsoNormal"> <span style="font-family: "consolas"; font-size: 14.0pt; line-height: 107%;">for(initialization; condition; increment)<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "consolas"; font-size: 14.0pt; line-height: 107%;">{<o:p></o:p></span></div> <div class="MsoNormal" style="text-indent: .5in;"> <span style="font-family: "consolas"; font-size: 14.0pt; line-height: 107%;"> Statements(s);<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "consolas"; font-size: 14.0pt; line-height: 107%;">}<o:p></o:p></span></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <span style="font-size: 16.0pt; line-height: 107%;">How this loop works is explained below:<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-size: 16.0pt; line-height: 107%;"><br /></span></div> <div class="MsoNormal" style="text-align: justify;"> <b><span style="font-size: 16.0pt; line-height: 107%;">Initialization: </span></b><span style="font-size: 16.0pt; line-height: 107%;">This is the very first part of for loop, here you can initialize the counter variable (variable of loop) e.g. i=1 or i=0. But this part is executed only once. This is to initialize the loop.<o:p></o:p></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;"><br /></span></div> <div class="MsoNormal" style="text-align: justify;"> <b><span style="font-size: 16.0pt; line-height: 107%;">Condition:</span></b><span style="font-size: 16.0pt; line-height: 107%;"> This the second part of for loop and the most important part, this part decides how many times the loop has to be executed.<o:p></o:p></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">If the condition is true the loop’s body is executed else it jumps to next statements.<o:p></o:p></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;"><br /></span></div> <div class="MsoNormal" style="text-align: justify;"> <b><span style="font-size: 16.0pt; line-height: 107%;">Increment:</span></b><span style="font-size: 16.0pt; line-height: 107%;"> if the condition is true there is an increment in the counter variable. The increment is done using increment operator “ ++ ”.<o:p></o:p></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">You can increment in different ways for example:<o:p></o:p></span></div> <div class="MsoListParagraphCxSpFirst" style="text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">                    <o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="margin-left: 2.0in; mso-add-space: auto; tab-stops: 133.85pt; text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">i++     //post increment<o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="margin-left: 2.0in; mso-add-space: auto; text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">++i     //pre increment<o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="margin-left: 2.0in; mso-add-space: auto; text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">1+i<o:p></o:p></span></div> <div class="MsoListParagraphCxSpMiddle" style="margin-left: 2.0in; mso-add-space: auto; text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">i+1<o:p></o:p></span></div> <div class="MsoListParagraphCxSpLast" style="margin-left: 133.85pt; mso-add-space: auto; text-align: justify;"> <br /></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">You can also increment for two or three times, it’s up to you that how many times you want, you can do this too<o:p></o:p></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;"><br /></span></div> <div class="MsoNormal" style="margin-left: .5in; text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">                          i+3 or i+4<o:p></o:p></span></div> <div class="MsoNormal" style="margin-left: .5in; text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;"><br /></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">After the increment the condition is evaluated again leaving the first pat this time, if the condition is true the loop executes further else it is terminated and jumps to the next statements<o:p></o:p></span></div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;"><br /></span></div> <div class="MsoNormal" style="margin-left: 1.75in; text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">        Here is flow diagram of control<o:p></o:p></span></div> <div class="MsoNormal" style="margin-left: .25in; text-align: justify;"> <!--[if gte vml 1]><v:shapetype id="_x0000_t75" coordsize="21600,21600" o:spt="75" o:preferrelative="t" path="m@4@5l@4@11@9@11@9@5xe" filled="f" stroked="f"> <v:stroke joinstyle="miter"/> <v:formulas> <v:f eqn="if lineDrawn pixelLineWidth 0"/> <v:f eqn="sum @0 1 0"/> <v:f eqn="sum 0 0 @1"/> <v:f eqn="prod @2 1 2"/> <v:f eqn="prod @3 21600 pixelWidth"/> <v:f eqn="prod @3 21600 pixelHeight"/> <v:f eqn="sum @0 0 1"/> <v:f eqn="prod @6 1 2"/> <v:f eqn="prod @7 21600 pixelWidth"/> <v:f eqn="sum @8 21600 0"/> <v:f eqn="prod @7 21600 pixelHeight"/> <v:f eqn="sum @10 21600 0"/> </v:formulas> <v:path o:extrusionok="f" gradientshapeok="t" o:connecttype="rect"/> <o:lock v:ext="edit" aspectratio="t"/> </v:shapetype><v:shape id="Picture_x0020_2" o:spid="_x0000_s1026" type="#_x0000_t75" style='position:absolute;left:0;text-align:left;margin-left:110.8pt; margin-top:22.6pt;width:267.55pt;height:350.35pt;z-index:251658240; visibility:visible;mso-wrap-style:square;mso-wrap-distance-left:9pt; mso-wrap-distance-top:0;mso-wrap-distance-right:9pt; mso-wrap-distance-bottom:0;mso-position-horizontal:absolute; mso-position-horizontal-relative:text;mso-position-vertical:absolute; mso-position-vertical-relative:text'> <v:imagedata src="file:///C:\Users\MUZAMM~1\AppData\Local\Temp\msohtmlclip1\01\clip_image001.png" o:title=""/> <w:wrap type="through"/> </v:shape><![endif]--><!--[if !vml]--><!--[endif]--><span style="font-size: 16.0pt; line-height: 107%;"><o:p></o:p></span></div> <div class="MsoListParagraphCxSpFirst"> <br /></div> <div class="separator" style="clear: both; text-align: center;"> <a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgsUl26dStN_d4AyOwhWfHbZhC8jx16-KNMsTfxZ9uSNxVdgHfHyglkx29vRqgD9dekINcvuanyqDRJoN4Tl_6_z1YaiB0pgo8AsXaaZpeqB1Qv2yHlTvDJLUNVofUw2rffngsj5IPRL8E/s1600/loop.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgsUl26dStN_d4AyOwhWfHbZhC8jx16-KNMsTfxZ9uSNxVdgHfHyglkx29vRqgD9dekINcvuanyqDRJoN4Tl_6_z1YaiB0pgo8AsXaaZpeqB1Qv2yHlTvDJLUNVofUw2rffngsj5IPRL8E/s400/loop.png" width="305" /></a></div> <div class="MsoListParagraphCxSpMiddle"> <br /></div> <div class="MsoListParagraphCxSpMiddle"> <br /></div> <div class="MsoNormal"> <span style="font-size: 20.0pt; line-height: 107%;">Example:<o:p></o:p></span></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <span style="color: #bc7a00; font-family: "consolas"; font-size: 11.5pt;">#include <iostream></span><b><span style="color: green; font-family: "consolas"; font-size: 11.5pt;"><o:p></o:p></span></b></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <b><span style="color: green; font-family: "consolas"; font-size: 11.5pt;">using</span></b><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;"> </span><b><span style="color: green; font-family: "consolas"; font-size: 11.5pt;">namespace</span></b><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;"> std;<o:p></o:p></span></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <br /></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <span style="color: #b00040; font-family: "consolas"; font-size: 11.5pt;">int</span><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;"> </span><span style="color: blue; font-family: "consolas"; font-size: 11.5pt;">main</span><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;">(){<o:p></o:p></span></div> <div style="margin-bottom: .0001pt; margin: 0in;"> <br /></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;">    </span><span style="color: #b00040; font-family: "consolas"; font-size: 11.5pt;">int</span><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;"> x;<o:p></o:p></span></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;">    <o:p></o:p></span></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <br /></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;">    </span><b><span style="color: green; font-family: "consolas"; font-size: 11.5pt;">for</span></b><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;">(i=0;i<=10;i++) </span><span style="color: #00b0f0; font-family: "consolas"; font-size: 11.5pt;">//the for loop, loop continues for 10 times</span><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;"><o:p></o:p></span></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <br /></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;">    {<o:p></o:p></span></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in; margin-left: .5in; margin-right: 0in; margin-top: 0in;"> <span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;">cout </span><span style="color: #666666; font-family: "consolas"; font-size: 11.5pt;"><<</span><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;"> </span><span style="color: #ba2121; font-family: "consolas"; font-size: 11.5pt;">“The squre is”</span><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;"> </span><span style="color: #666666; font-family: "consolas"; font-size: 11.5pt;"><< i*i <<</span><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;"> endl; </span><span style="color: #00b0f0; font-family: "consolas"; font-size: 11.5pt;">// pints the square of i</span><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;"><o:p></o:p></span></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;">    }<o:p></o:p></span></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;">   <o:p></o:p></span></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;">    </span><b><span style="color: green; font-family: "consolas"; font-size: 11.5pt;">return</span></b><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;"> </span><span style="color: #666666; font-family: "consolas"; font-size: 11.5pt;">0</span><span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;">;<o:p></o:p></span></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <br /></div> <div class="MsoNormal" style="line-height: 16.3pt; margin-bottom: .0001pt; margin-bottom: 0in;"> <span style="color: #1e1e1e; font-family: "consolas"; font-size: 11.5pt;">}<o:p></o:p></span></div> <div class="MsoNormal"> <br /></div> <div class="MsoNormal"> <span style="font-size: 16.0pt; line-height: 107%;">The output of the following program is<o:p></o:p></span></div> <div class="MsoNormal"> <span style="font-family: "consolas"; font-size: 14.0pt; line-height: 107%;">0  1  4  9  16  25  36  49  64  81  100<o:p></o:p></span></div> <div class="MsoNormal" style="tab-stops: 386.05pt; text-align: justify;"> <span style="font-size: 20.0pt; line-height: 107%;">                                                                                      <o:p></o:p></span></div> <div class="MsoNormal"> </div> <div class="MsoNormal" style="text-align: justify;"> <span style="font-size: 16.0pt; line-height: 107%;">This program has printed squares of numbers starting from 1 to 10. We only need to specify the one statement.<o:p></o:p></span><br /> <span style="font-size: 16.0pt; line-height: 107%;"><br /></span> <br /> <span style="font-size: 16.0pt; line-height: 107%;"><br /></span></div>

The for loop in C++

The for loop is the easiest loop in C++ to understand. All elements of this loop are in one place contrary to those remaining two (while, d...

Read more »