ns1 lation, computational linguistics, symbolic mathematics, text editing, and document formatting. Developers of string-processing languages are in a less well-defined position than developers of numerical processing languages. While mathematical notation for numerical computation has developed over centuries, and its current form is widely known and fairly well standardized, string processing is a new area. There is no general agreement on what operations should be performed in string processing, nor is there a standard notation. The developers of stringprocessing languages started largely without conventions. As a result, notation, program structure, and approach to problem formulation are often radically different from those of more conventional programming languages. Operations on Strings While there were no generally agreed-upon string operations when string-processing languages were first developed, four operations have achieved general acceptance: conca

In programming contexts, the term string usually refers to a sequence of characters. For Example, ABC is a string of three characters. Strings are more prevalent in computing than is generally realized. In most cases, computer input is in the form of strings (e.g. commands entered at a terminal). Similarly, computer output is in the form of strings since printed lines are simply strings of characters. The facilities of the most widely used programming languages are concentrated on numerical and business data processing. However, a substantial amount of string processing is performed. For Example compilers accept strings as input, analyze them, and produce either bit or character strings as output. Command interpreters