What is the sequence point?

Sequential point in computer programming is the moment that occurs during the program, when the value of the variable was completely calculated, without changes waiting from previous operations and there is no calculation. There are a number of places where sequence points exist - primarily defined in the C language standard - for example, before performing a code inside the function, at the end of control terms in commands such as "Pro" and "IF", and at the end of any complete expression, such as a simple line of C code. Some reasons for defining a sequence point are to avoid situations that are ambiguous, lead to undefined behavior, or can confuse the compiler and generate a code that is unpredictable. In many cases, programmers do not care about the sequential point, although this concept is very important when creating a compiler.

The point of the Point sequence in the C programming language is in the a = a + b;. In this expression, the sequence is sequence; After completion ofThe value of A will be evaluated and no residual calculations will be made until another expression begins. The equal mark is not a sequential point, because the value A can be adjusted by the compiler in any order throughout the expression.

The main rule of the sequential point is that no variable will be accessible more than once between points for any other purpose than to calculate the change in value. The violation of this rule is best expressed when assigning the field value. If there is a variable and a field called I, then it is grammatically to write the term i [a] = a ++. Here, access to the variable is more than once for the purpose other than the evaluation of its current value; Namely, it is used as an AN index in field I. This means that the compiler can increase and before it is used as an index or after use, and create unpredictable behavior that cannot be relying on the program.

sequential point can be basicallyconsider it a way to ensure that the commands can and consistently evaluated and made by a compiler. This also allows the compiler to use optimization strategies because the defined behavior is predictable. There are three main instances of sequence points within the language standard C, when the function starts to perform, at the moment of logical operators and commas, and at the end of a complete expression that ends with semikolone, as most statements c