Programming LanguagesProgramming languages and Natural LanguagesNatural Languages use:Programming Languages use:WritingStyleHow to use programming languages:Programming Languages...Programming Languages give instructions:Storing DataProgramming LanguagesV22.0002Deena Engel’s classProgramming languages and Natural LanguagesThey both use:•syntax (e.g. punctuation) •grammar (“well formed sentences”) •parts of speech (reserved words) •semantics (meanings of variables, objects similar to pronouns)Natural Languages use:Syntax: punctuation and spacing Grammar: to create “well formed sentences” (e.g. subject-verb-object) Parts of speech: nouns, verbs, adjectivesSemantics: the meaning of the words and what they represent (e.g. in English, “cat” refers to a furry, four-pawed mammal in the Great Cats family)Programming Languages use:Syntax: punctuation such as parentheses, braces, brackets, semicolons, etc Grammar: well-formed structures such as “for loops” and othersParts of speech: different data types such as integers, characters, datesSemantics: the meaning of the symbols, e.g. x = 3; or the use of reserved words.Writing Steps in writing code in a programming language:Source code Compiler  Machine languageStyle•Style counts … in both kinds of languages!•In natural language … style distinguishes the type of writing e.g. the differences between a sonnet by Shakespeare and my weekly shopping list…•In a programming language, style is both important to make the program readable and in terms of efficiencyHow to use programming languages:•Natural languages: can be used to tell a story … and other purposes … as well as to give instructions.•Cookbooks and how-to books provide instructions in a natural language: “mix ½ cup of sugar into the butter” •The instructions might include decisions: “if these are chocolate chip cookies, add chocolate chips and shredded coconut ; otherwise just add shredded coconut”).Programming Languages...Give instructions to the computer!•A computer program is like a cookie recipe except that the computer follows the instructions!Programming Languages give instructions:•Any series of repeated instructions can be called an algorithm. In many cases, the programming language mirrors what you would do if you were doing the task manually:•Keeping a checkbook: order the amounts by the date of the check; if it’s a check, subtract the amount; if it’s a deposit, add the amount; then print the running total•Create an index for a textbook: read the text; discard extra words (“the”, “and”); list the important terms and their pages; write it up as an indexStoring DataProgramming languages are also used to track information in logical ways: For example, one can write a program to creating a database of names, addresses and telephone numbers. We will look at this means of expression as