Skip to main content

Lesson 2: Using If statements in C, C++


Basic Syntax of IF - ELSE Statement in C , C++ with example 

The ability to control the flow of your program, letting it make decisions on what code to execute, is valuable to the programmer. The if statement allows you to control if a program enters a section of code or not based on whether a given condition is true or false. One of the important functions of the if statement is that it allows the program to select an action based upon the user's input. For example, by using an if statement to check a user-entered password, your program can decide whether a user is allowed access to the program.

Without a conditional statement such as the if statement, programs would run almost the exact same way every time, always following the same sequence of function calls. If statements allow the flow of the program to be changed, which leads to more interesting code.

Before discussing the actual structure of the if statement, let us examine the meaning of TRUE and FALSE in computer terminology. A true statement is one that evaluates to a nonzero number. A false statement evaluates to zero. When you perform comparison with the relational operators, the operator will return 1 if the comparison is true, or 0 if the comparison is false. For example, the check 0 == 2 evaluates to 0. The check 2 == 2 evaluates to a 1. If this confuses you, try to use a printf statement to output the result of those various comparisons (for example printf ( "%d", 2 == 1 );)

When programming, the aim of the program will often require the checking of one value stored by a variable against another value to determine whether one is larger, smaller, or equal to the other.

There are a number of operators that allow these checks.

Here are the relational operators, as they are known, along with examples:
>     greater than              5 > 4 is TRUE
<     less than                 4 < 5 is TRUE
>=    greater than or equal     4 >= 4 is TRUE
<=    less than or equal        3 <= 4 is TRUE
==    equal to                  5 == 5 is TRUE
!=    not equal to              5 != 4 is TRUE
It is highly probable that you have seen these before, probably with slightly different symbols. They should not present any hindrance to understanding. Now that you understand TRUE and FALSE well as the comparison operators, let us look at the actual structure of if statements.

Basic Syntax of IF - ELSE Statement in C , C++ with example 

 


Comments

Popular posts from this blog

AGRICULTURAL SCIENTIST RECRUITMENT BOARD

Agricultural Research Service

National
Eligibility Test/ Senior Research Fellowship Examination 

The Agricultural Scientists Recruitment Board (ASRB)
 holds a Competitive Examination for recruiting Scientists of the ARS in the pay scale of Rs. 8,000-13,500 in the ICAR Institutes, combined with National Eligibility Test (NET) for recruitment of Lecturers and Assistant Professors by the State Agricultural Universities (SAUS) and for award of ICAR Senior Research Fellowships.

The selected candidates for Agricultural Research Service must serve in the institutes to which they are posted until they find appointment for higher positions through selection at other institutes.

(i) Candidates successful in ARS are appointed as Scientists in the Indian Council of Agricultural Research in the pay scale of Rs. 8,000-13,500.

(ii) Candidates clearing the National Eligibility Test are recommended to various State Agricultural Universities who will consider them for appointment as Lecturers or Assistant Pro…

CIVIL SERVICES' (I.A.S.) EXAMINATION

The Union Public Service Commission (U.P.S.C.) conducts Civil Services' Examination once a year in two stages. The Preliminary Examination (Objective Type) for selection of candidates for the Main Examination is held in the month of May.

The Civil Services Main Examination
 is held in the months of October/November. Blank application forms and other particulars are published in the Employment News, generally in the month of December.

The last date for the submission of applications to the Secretary, Union Public Service Commission, Dholpur House, Shahjahan Road, NewDelhi-11001 1 is usually the last week of January of the year of examination.

The Combined Civil Services Examination is conducted for Recruitment to the following Services/Posts:

1. Indian Administrative Service.
2. Indian Foreign Service.
3. Indian Police Service.
4. Indian P & T Accounts & Finance Service, Group 'A'.
5. Indian Audit and Accounts Service, Group 'A'.
6. Indian Customs and Central Excise S…

HSC Exam Time Table 2013 Arts, Commerce, Science

HSC Exam Time Table 2013:- Date: 21 Feb 2013 (Thursday)

Paper: (Marathi / Gujarati / Kannada / Sindi / Malyalam / Tamil / Telugu / Punjabi / Bengali
Time: 11.00 am to 2.00 pm

Date: 22 Feb 2013 (Friday)

Paper: Hindi
Time: 11.00 am to 2.00 pm
Paper: German / Andhramagadhi / Persian
Time: 3.00 am to 6.00 pm

Date: 23 Feb 2013 (Saturday)

Paper: English
Time: 11.00 am to 2.00 pm

Date: 25 Feb 2013 (Monday)

Paper: Secretarial Practice
Time: 11.00 am to 2.00 pm
Paper: Physics
Time: 11.00 am to 2.00 pm
Paper: Political Science
Time: 3.00 am to 6.00 pm

Date: 27 Feb 2013 (Wednesday)

Paper: Book Keeping & Accoutancy
Time: 11.00 am to 2.00 pm
Paper: Chemistry (will Be held on 26 March)
Time: 11.00 am to 2.00 pm
Paper: Philosophy
Time: 3.00 am to 6.00 pm

Date: 1 March 2013 (Friday)

Paper: Mathematics & Statistics Paper (Revised)
Time: 11.00 am to 2.00 pm
Paper: Mathematics & Statistics - I (Commerce)
Time: 11.00 am to 1.00 pm
Paper: Sociology
Time: 3.00 am to 6.00 pm

Date: 2 March 2013 (Saturd…