C: Switch Statements. Sometimes when creating a C program, you run into a situation in which you want to compare one thing to a number of other things. Let's say, for example, that you took a character from the user and wanted to compare this to a number of characters to perform different actions. Demikianlah Pembahasan Mengenai Bentuk Umum IF Bersarang dalam Program c dan program lainnya serta contoh program c if bersarang dengan menggunakan dev c. Program c if bersarang ini sudah termasuk didalamnya Program c If, Program c If Else, dan Program C If Else If, namun untuk lebih memahaminya dan lebih detail pembahasannya. The task of the above code is that is first asks for your grades number example: 90. Then using the if else statement makes name2 variable to 1 if name is = 90, 2 if name = 80, 3 if name = 70 and 4 if name. If-else-if ladder in C/C. Here, a user can decide among multiple options. The C if statements are executed from the top down. As soon as one of the conditions controlling the if is true, the statement associated with that if is executed, and the rest of the C else-if ladder is bypassed.
The #if directive, with the #elif, #else, and #endif directives, controls compilation of portions of a source file. If the expression you write (after the #if) has a nonzero value, the line group immediately following the #if directive is kept in the translation unit.
elif-parts elif-line text
Each #if directive in a source file must be matched by a closing #endif directive. Any number of #elif directives can appear between the #if and #endif directives, but at most one #else directive is allowed. The #else directive, if present, must be the last directive before #endif.
The #if, #elif, #else, and #endif directives can nest in the text portions of other #if directives. Each nested #else, #elif, or #endif directive belongs to the closest preceding #if directive.
All conditional-compilation directives, such as #if and #ifdef, must match a closing #endif directive before the end of file. Otherwise, an error message is generated. When conditional-compilation directives are contained in include files, they must satisfy the same conditions: There must be no unmatched conditional-compilation directives at the end of the include file.
Macro replacement is done within the part of the line that follows an #elif command, so a macro call can be used in the constant-expression.
The preprocessor selects one of the given occurrences of text for further processing. A block specified in text can be any sequence of text. It can occupy more than one line. Usually text is program text that has meaning to the compiler or the preprocessor.
The preprocessor processes the selected text and passes it to the compiler. If text contains preprocessor directives, the preprocessor carries out those directives. Only text blocks selected by the preprocessor are compiled.
The preprocessor selects a single text item by evaluating the constant expression following each #if or #elif directive until it finds a true (nonzero) constant expression. It selects all text (including other preprocessor directives beginning with #) up to its associated #elif, #else, or #endif.
If all occurrences of constant-expression are false, or if no #elif directives appear, the preprocessor selects the text block after the #else clause. When there's no #else clause, and all instances of constant-expression in the #if block are false, no text block is selected.
The constant-expression is an integer constant expression with these additional restrictions:
Expressions must have integral type and can include only integer constants, character constants, and the defined operator.
The expression can't use
sizeofor a type-cast operator.
The target environment may be unable to represent all ranges of integers.
The translation represents type int the same way as type long, and unsigned int the same way as unsigned long.
The translator can translate character constants to a set of code values different from the set for the target environment. To determine the properties of the target environment, use an app built for that environment to check the values of the LIMITS.H macros.
The expression must not query the environment, and must remain insulated from implementation details on the target computer.
C++ If Else Program
The preprocessor operator defined can be used in special constant expressions, as shown by the following syntax:
This constant expression is considered true (nonzero) if the identifier is currently defined. Otherwise, the condition is false (0). An identifier defined as empty text is considered defined. The defined operator can be used in an #if and an #elif directive, but nowhere else.
In the following example, the #if and #endif directives control compilation of one of three function calls:
The function call to
credit is compiled if the identifier
CREDIT is defined. If the identifier
DEBIT is defined, the function call to
debit is compiled. If neither identifier is defined, the call to
printerror is compiled. Both
credit are distinct identifiers in C and C++ because their cases are different.
The conditional compilation statements in the following example assume a previously defined symbolic constant named
The first #if block shows two sets of nested #if, #else, and #endif directives. The first set of directives is processed only if
DLEVEL > 5 is true. Otherwise, the statements after #else are processed.
Dev C++ If Else Nested Lecture Show
The #elif and #else directives in the second example are used to make one of four choices, based on the value of
DLEVEL. The constant
STACK is set to 0, 100, or 200, depending on the definition of
DLEVEL is greater than 5, then the statement
If Else C++ One Line
is compiled, and
STACK isn't defined.
A common use for conditional compilation is to prevent multiple inclusions of the same header file. In C++, where classes are often defined in header files, constructs like this one can be used to prevent multiple definitions:
Shape of you without auto tune. Missed that high note? Like a spellchecker or photo editing software can save us from our mistakes, the audio program Auto-Tune can correct a singer's bad notes and wavering pitch.Although the program is best known for the singing-through-a-fan, robotic vocal style that has dominated pop radio in recent years with stars like Lady Gaga, T-Pain and countless others, Auto-Tune is in fact widely used in the studio and at concerts to make artists'.' Quite frankly, use of Auto-Tune happens on almost all vocal performances you hear on the radio,' said Marco Alpert, vice president of marketing for Antares Audio Technologies, the company that holds the trademark and patent for Auto-Tune.The beauty of Auto-Tune, Alpert said, is that instead of an artist having to sing take after take, struggling to get through a song flawlessly, Auto-Tune can clean up small goofs.' It used to be that singers would have to sing a song over and over, and by that time you've lost the emotional content of the performance,' Alpert said. With Auto-Tune, that's OK.
The preceding code checks to see if the symbolic constant
EXAMPLE_H is defined. If so, the file has already been included and doesn't need reprocessing. If not, the constant
EXAMPLE_H is defined to mark EXAMPLE.H as already processed.
Visual Studio 2017 version 15.3 and later: Determines whether a library header is available for inclusion: