Syntax error

For 2003 film, see Syntax Error (film).

In computer science, a syntax error refers to an error in the syntax of a sequence of characters or tokens that is intended to be written in a particular programming language.

For compiled languages syntax errors occur strictly at compile-time. A program will not compile until all syntax errors are corrected. For interpreted languages, however, not all syntax errors can be reliably detected until run-time, and it is not necessarily simple to differentiate a syntax error from a semantic error; many don't try at all.

A syntax error may also occur when an invalid equation is entered into a calculator. This can be caused, for instance, by opening brackets without closing them, or less commonly, entering several decimal points in one number.

In Java the following is a syntactically correct statement:

  1. system.out.println("Hello World");

while the following is not:

  1. system.out.+println("Hello World");

A compiler will flag a syntax error when given source code that does not meet the requirements of the language grammar.