How To Use If Else In Dev C++

  1. C++ Else If Syntax
  2. C++ If Else Program
  3. How To Use If Else In Dev C++ Interview
  4. If Else Statements In C
  5. C++ If Then Else
  6. How To Use If Else In Dev C++ Code

Nested if in C is using more than one if statements in the same scope. The if statement is a decision-making statement that allows taking decisions based upon the condition specified. When there is more than one condition and they are dependent on one another, then if statement can be nested.

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An if-else statement controls conditional branching. Statements in the if-branch are executed only if the condition evaluates to a non-zero value (or true). If the value of condition is nonzero, the following statement gets executed, and the statement following the optional else gets skipped. Otherwise, the following statement gets skipped, and if there's an else then the statement following the else gets executed.

condition expressions that evaluate to non-zero are:

  1. If else statements in C is also used to control the program flow based on some condition, only the difference is: it's used to execute some statement code block if the expression is evaluated to true, otherwise executes else statement code block.
  2. If else statement in C Sometimes you have a condition and you want to execute a block of code if condition is true and execute another piece of code if the same condition is false. This can be achieved in C using if-else statement.
  3. C if, if.else and Nested if.else Integers which are perfectly divisible by 2 are called even numbers. And those integers which are not perfectly divisible by 2 are not known as odd number. To check whether an integer is even or odd, the remainder is calculated when it is divided by 2 using modulus operator%.
  4. C if.else The if statement can have an optional else clause.
  • true
  • a non-null pointer,
  • any non-zero arithmetic value, or
  • a class type that defines an unambiguous conversion to an arithmetic, boolean, or pointer type. (For information about conversions, see Standard Conversions.)

Syntax

init-statement:
expression-statement
simple-declaration

condition:
expression
attribute-specifier-seqoptdecl-specifier-seqdeclaratorbrace-or-equal-initializer

statement:
expression-statement
compound-statement

expression-statement:
expressionopt;

How to use if else in dev c++ interview

C++ Else If Syntax

compound-statement:
{statement-seqopt}

statement-seq:
statement
statement-seqstatement

if-branch:
statement

else-branch:
statement

selection-statement:
ifconstexpropt17(init-statementopt17condition)if-branch
ifconstexpropt17(init-statementopt17condition)if-branchelseelse-branch

17 This optional element is available starting in C++17.

if-else statements

In all forms of the if statement, condition, which can have any value except a structure, is evaluated, including all side effects. Control passes from the if statement to the next statement in the program unless the executed if-branch or else-branch contains a break, continue, or goto.

The else clause of an if...else statement is associated with the closest previous if statement in the same scope that doesn't have a corresponding else statement.

Example

This sample code shows several if statements in use, both with and without else:

if statement with an initializer

Starting in C++17, an if statement may also contain an init-statement expression that declares and initializes a named variable. Use this form of the if-statement when the variable is only needed within the scope of the if-statement. Microsoft-specific: This form is available starting in Visual Studio 2017 version 15.3, and requires at least the /std:c++17 compiler option.

Example

if constexpr statements

C++ If Else Program

Starting in C++17, you can use an if constexpr statement in function templates to make compile-time branching decisions without having to resort to multiple function overloads. Microsoft-specific: This form is available starting in Visual Studio 2017 version 15.3, and requires at least the /std:c++17 compiler option.

Example

This example shows how you can write a single function that handles parameter unpacking. No zero-parameter overload is needed:

See also

Selection Statements
Keywords
switch Statement (C++)

Conditional statements, also known as selection statements, are used to make decisions based on a given condition. If the condition evaluates to True, a set of statements is executed, otherwise another set of statements is executed.

The if Statement: The if statement selects and executes the statement(s) based on a given condition. If the condition evaluates to True then a given set of statement(s) is executed. However, if the condition evaluates to False, then the given set of statements is skipped and the program control passes to the statement following the if statement. The syntax of the if statement is

The if-else Statement: The if – else statement causes one of the two possible statement( s) to execute, depending upon the outcome of the condition.

The syntax of the if-else statements is

Here, the if-else statement comprises two parts, namely, if and else. If the condition is True the if part is executed. However, if the condition is False, the else part is executed.

To understand the concept of the if -else statement, consider this example.

Example : A code segment to determine the greater of two numbers

Nested if-else Statement: A nested if-else statement contains one or more if-else statements. The if else can be nested in three different ways, which are discussed here.

• The if – else statement is nested within the if part.

The syntax is

• The if-else statement is nested within the else part.

The syntax is

• The if-else statement is nested within both the if and the else parts.

The syntax is

To understand the concept of nested if-else, consider this example.

Example : A code segment to determine the largest of three numbers

The if-else-if ladder, also known as the if-else-if staircase, has an if-else statement within the outermost else statement. The inner else statement can further have other if-else statements.

The syntax of the if -e1se- if ladder is

To understand the concept of the if-else-if ladder, consider this example.

Example: A program to determine whether a character is in lower-case or upper case

The output of this program is

Enter an alphabet: $

How To Use If Else In Dev C++ Interview

It is not an alphabet

Conditional Operator as an Alternative: The conditional operator ‘? :’ selects one of the two values or expressions based on a given condition. Due to this decision-making nature of the conditional operator, it is sometimes used as an alternative to if-else statements. Note that the conditional operator selects one of the two values or expressions and not the statements as in the case of an if-else statement. In addition, it cannot select more than one value at a time, whereas if-else statement can select and execute more than one statement at a time. For example, consider this· statement.

If Else Statements In C

This statement assigns maximum of x and y to max

The switch Statement: The switch statement selects a set of statements from the available sets of statements. The switch statement tests the value of an expression in a sequence and compares it with the list of integers or character constants. When a match is found, all the statements associated with that constant are executed.

The syntax of the switch statement

The C++ keywords case and default provide the list of alternatives. Note that it is not necessary for every case label to specify a unique set of statements. The same set of statements can be shared by multiple case labels.

Program

The keyword default specifies the set of statements to be executed in case no match is found. Note that there can be multiple case labels but there can be only one default label. The break statements in the switch block are optional. However, it is used in the switch block to prevent a fall through. Fall through is a situation that causes the execution of the remaining cases even after a match has been found. In order to prevent this, break statements are used at the end of statements specified by each case and default. This causes the control to immediately break out of the switch block and execute the next statement.

C++ If Then Else

To understand the concept of switch statement, consider this code segment.

Example : A code segment to demonstrate the use of switch statement

In this example, depending upon the input, an appropriate message is displayed. That is, if 2 are entered, then the message Option 2 is selected is displayed. In case, 5 is entered, then the message Invalid option! is displayed.

How To Use If Else In Dev C++ Code

Similar to if and if-else statements, switch statements can also be nested within one another. A nested switch statement contains one or more switch statements within its case label or default label (if any).

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