CSE 220 Final Review Exam 86 Questions with Verified Answers

CSE 220 Final Review Exam 86 Questions with Verified Answers A tour of computer systems summary slide - ANSWERS - Architectural details matter -Bus widths -Numeric properties -Performance details - C and POSIX are just one possible system - All systems have those details - Software correctness can be critically important an array can be initialized all at once at declaration, how? - ANSWERS An array can be initialized all at once at declaration. int array [10] = { 0 , 3 , 5 , 0 , 0 , 1 , 0 , 0 , 2 , 0 }; This is called a static initializer. Static initializers can be used only at declaration. int array [3]; array = { 1 , 3 , 5 }; /* syntax error */ are all arguments pass-by-value? - ANSWERS yes, they are copies of whatever is passed to them Are non-zero values true or false? - ANSWERS true k&r 2.7 Arrays - ANSWERS - C arrays are a series of contiguous memory locations - declared with [ ] the size is between the [ ] Because heap allocations have no obvious size... - ANSWERS out-of-bounds access is easy, and the compiler will not catch this bitwise 0 is true or false? - ANSWERS false bitwise non 0 is true or false? - ANSWERS true boolean false and false results are exactly? - ANSWERS 0 boolean true and true results are exactly? - ANSWERS 1 Bus - ANSWERS has a width which is literally the number of wires it has C a typed language? - ANSWERS - C is a typed language - every variable has a type and is declared - every value assigned to a variable must match that type C strings - ANSWERS are just arrays, not associated with a length (you have to count characters to know how long they are) calloc() - ANSWERS void * calloc ( size_t nmemb , size_t size ) ; The closely-related calloc() allocates cleared memory. The memory returned by malloc() is uninitialized. The memory returned by calloc() is set to bitwise zero. Note that invocation is slightly different! can pointers be compared? - ANSWERS - yes under certain circumstances, if p and q point to members in the same array then ==, !=, <=, >= etc work properly - p<q is true if p points to an earlier member of the array than q does k&r 5.4 Can structures be compared? - ANSWERS NO conditional instruction flow, what is lost in compiling? - ANSWERS structure of program. semantics (meaning) remain though Conditionals and Control Flow Summary slide - ANSWERS - All nonzero values are true conditions in C. - All Boolean expressions use 1 for true. - The bool -keyword holds only 0 or 1. C uses short-circuit evaluation of Boolean