![]() In the first case, the statement will return 1, and in the second case, the statement will return true. Then, it will decompose to one of false or 1 or true or 1. The other form, x ~= 0 or 1 will first evaluate x ~= 0 (which may return true or false, depending on the value of x). Using these rules, x ~=(0 or 1) will decompose to x ~= 0 (after applying the or operator) and this will return 'true' if x is anything other than 0, including 1, which is undesirable. The relational operator ~= is the inverse of the equality operator = it returns true if its arguments are different types (x is a number, right?), and otherwise compares its arguments normally. ![]() The logical operator or "returns its first argument if this value is different from nil and false otherwise, or returns its second argument". Everything has a lower precedence than parentheses.Īs a result, when evaluating x ~=(0 or 1), the interpreter will first compute 0 or 1 (because of the parentheses) and then x ~= the result of the first computation, and in the second example, it will compute x ~= 0 and then apply the result of that computation to or 1. or has a lower precedence than ~=, just as addition in mathematics has a lower precedence than multiplication. Each operator has a precedence which determines the order in which it will be evaluated. However, Lua does not parse this based on the rules of English grammar, it parses it in binary comparisons of two elements based on its order of operations. You apply the subject with the verb to each item in the set. In the ordinary understanding of that statement, "x" is the subject, "is not equal to" is the predicate or verb phrase, and "zero or one" is the object, a set of possibilities joined by a conjunction. When you read x ~=(0 or 1) or x ~= 0 or 1 it's natural to parse this as you would the sentence "x is not equal to zero or one". ![]() Yes, your immediate problem can be solved by writing x ~= 0 and x ~= 1, but I'll go into a little more detail about why your attempted solution doesn't work. Tutor the students that don’t get it for some extra cash or free pizza.Your problem stems from a misunderstanding of the or operator that is common to people learning programming languages like this. See, it really is an advanced class :rolleyes: Tough it out, get the easy A. Programming the modern computer will be covered … (Prog 202) Advanced Programming: Introduction to Java. ![]() Programming bean roasters, grinders and air tight packing machines is also covered. This class will cover all aspects of programming modern coffee equipment from simple K-cup to more complex cafe-mocha-steamed-extra shots-no whipped cream factory devices. Note: Discussions around VHS vs Beta vs Optical Disk will be covered in a joint session with Tech 102. Initial setup of the time and date, cable / antenna, daily, weekly and special event programming and the use of “plus time” to capture sporting events of variable length. (Prereq Prog 101) This class will cover programming the home VCR. (Prog 102) Introduction to programming - The VCR. More advanced topics like the “Popcorn” and “Pizza” buttons will be covered in a special Saturday Seminar that is open to the public. Class will cover all aspects of programming: Standard time lengths, use of delayed start, management of power levels, defrost cycles. (Prog 101) Introduction to programming - The microwave. That’s why a class called Advanced is in actuality an Intro to Java course.Īs a university professor, I can tell you how these classes get named:
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