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Hello World

Syntax in C

The rules that dictate the correct format of code for a specific programming language are known as syntax.

Examples of syntax in C are:

  • All statements must end with a semicolon, ;
  • Keywords and other code elements are case-sensitive

When compiling C code, an error will occur when the syntax of the code is incorrect.

// Statements must end in a semicolon (;) // correct printf("Hello World!"); // error printf("Hello World!") // Code elements are case sensitive // correct printf("Hello World!"); // error PRINTF("Hello World!");

Escape Sequences

In C, an escape sequence is a non-visual character used within a string.

\n is an escape sequence that adds a newline to a string. \t is an escape sequence that adds a tab of spaces to a string.

// \n acts as a newline in a string printf("Hello\nWorld!"); // Outputs: Hello // World! // \t acts as a tab in a string printf("Hello\tWorld!"); // Outputs: Hello World!

Comments in C

In C, comments are text within code that will be ignored by the compiler. They are used to document code.

Line comments begin with a double forward slash, //. All text after // will be part of the comment until a new line is reached.

Block comments begin with a forward slash and asterisk, /* and end with an asterisk and forward slash, */. Block comments can span multiple lines as new lines are part of the comment.

// Comments /* This review content is about comments and how they can be used to document code */ // This is a line comment /* This is a block comment */

Compiling C Code with gcc

gcc is an application used to compile C programs into an executable that can run on the target computer. gcc stands for GNU Compiler Collection.

gcc compiles C code using the code file as an unflagged command-line argument. The output executable file will be called a.out. The -o flag followed by some text can be used to designate the name of the output executable file.

gcc script.c gcc script.c -o myProgram