Question: What are setjmp() and longjmp() Functions in Standard C Library. Explain with Examples When to Use them Answer: ‘setjmp()’ and ‘longjmp()’ functions provide a powerful mechanism similar to ‘goto’ but not restricted to just current function. This mechanism is useful in situations where there’s a deeply nested function calls and when error gets detected, … Read more
Question: What are Date and Time Conversion Functions in Standard C Library Answer: We know that ‘time()’ function returns value of type ‘time_t’ which is a 32-bit signed value on many implementations. The value returned is no. of seconds from some arbitrary epoch, for ex. 00:00:00 January 1, 2014. In order to obtain current date … Read more
Question: What is Time of Day Function in Standard C Library? Answer: Standard library provides collection of functions for dealing with time of the day and current date. ‘time()’ function is prototyped below time_t time(time_t *returned_value); On many implementations, time_t value is defined as signed 32-bit quantity. Note that argument passed to ‘time()’ if not … Read more
Question: What is Processor Time Function in Standard C Library? Answer: ‘time.h’ header provides a time function that returns amount of processor time used by the program since it began executing. Though this is just an approximation. If more precise time estimation is required, call the ‘clock()’ function at the beginning of main() and subtract … Read more
Question: What are Date and Time Functions in Standard C Library? Answer: Standard library gives a nice collection of functions which allow us to deal with date and time related computations. These include ‘clock()’ function which returns amount of processor time used by the program, ‘time()’ function returns no. of seconds from an arbitrary epoch, … Read more
Question: What are Floor, Ceiling, Absolute Value and Remainder Functions in Standard C Library? Answer: Standard C Library defines ‘floor()’, ‘ceil()’, ‘fabs()’ and ‘fmod()’ functions with return values and their arguments as type ‘double’ because of greater range of double values over ‘integer’ values. These are prototyped as below, double floor(double value); double ceil(double value); … Read more
Question: What is Power Function in Standard C Library? Answer: There are two functions in this family which are defined in ‘math.h’ header and are prototyped below double pow(double x, double y); double sqrt(double value); Power ‘pow()’ function returns x raised to power y. Since logarithms may be used to compute the exp. ‘x^y’, x … Read more
Question: What are Various Logarithmic and Exponential Functions in Standard C Library? Answer: Mentioned below are logarithmic and exponential functions defined in ‘math.h’ header. double log(double value); /* computes natural logarithm */ double log10(double value); double exp(double value); ‘log()’ function computes logarithm of given argument to the base e. This is called “natural logarithm”. ‘log10()’ … Read more
Question: What are Different Hyperbolic Functions in Standard C Library? Answer: We have following hyperbolic functions defined and prototyped in ‘math.h’ header. double sinh(double angle); double cosh(double angle); double tanh(double angle); These functions return the hyperbolic sine, hyperbolic cosine and hyperbolic tangent of their arguments respectively. Each function takes angle, in radians, as its argument. … Read more
Question: What are Various Trigonometric Functions in Standard C Library? Answer: Following trigonometric functions are defined in ‘math.h’ header. double sin(double angle); double cos(double angle); double tan(double angle); double asin(double angle); double acos(double angle); double atan(double angle); double atan2(double x, double y); Recall that PI radians equals 180 degrees. Functions ‘sin()’, ‘cos()’ and ‘tan()’ take … Read more
