Curly bracket programming language

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Curly brace or bracket programming languages are those which use balanced brackets ({ and }, also known as "brace brackets" or simply "braces") to make blocks in their syntax or formal grammar, mainly due to being C-influenced.

Contents

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Statements and blocks

The name derives from the common syntax of the languages, where blocks of statements are enclosed in curly brackets. For example (using BSD/Allman indent style, one of many stylistic ways to format a program): 

for (int i = 0; i < 10; i++)
{
   printf("%d", i);
   doTask(i);
}

Languages in this family are sometimes referred to as C-style, because they tend to have syntax that is strongly influenced by C syntax. Beside the curly brackets, they often inherit other syntactic features, such as using the semicolon as a statement terminator (not as a separator), and the three-part "for" statement syntax as shown above.

Generally, these languages are also considered "free-form languages", meaning that the compiler considers all whitespace to be the same as one blank space, much like HTML. Considering that, the above code could be written: 

for(int i=0;i<10;i++){printf("%d",i);doTask(i);}

but this is not recommended, as it becomes nearly impossible for a person to read after the program grows beyond a few statements.

There are many other ways to identify statement blocks, such as ending keywords that may match beginning keywords (in Ada, Pascal, REXX, and Visual Basic), the Off-side rule of indentation (in Python), or other symbols such as parentheses (in Lisp). These ways are not necessarily exclusive: whereas indentation is the default in Haskell, curly brackets can be used when desired.

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Loops

In C, C++, C#, and Java: 

while (Boolean expression) {
    statement(s)
}

do {
    statement(s)
} while (Boolean expression);

for (initialisation; termination condition; incrementing expr) {
    statement(s)
}
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Conditional statements

In C, C++, C#, and Java: 

if (Boolean expression)
{
    statement(s)
}

if (Boolean expression)
{
    statement(s)
} 
else
{
    statement(s)
}

if (Boolean expression)
{
    statement(s)
} 
else if (Boolean expression)
{
    statement (s)
}
...
else
{
    statement(s)
}

switch (integer expression)
{
    case constant integer expr:
         statement(s)
         break;
    ...
    default:
         statement(s)
         break;
}
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Exception handling

In [[C++]], C# and Java: 

try
{
    statement(s)
}
catch (exception type)
{
    statement(s)
}
catch (exception type)
{
    statement(s)
}
finally
{
    statement(s)
}

Objective-C has the same syntax starting with gcc 3.3 and Apple MacOS X 10.3 , but with an at sign in front of the keywords (@try, @catch, @finally).

C++ does not have finally, but otherwise looks similar. C has nothing like this, though some compilers vendors added the keywords __try and __finally to their implementation.

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Languages

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