C language is a process-oriented abstract general programming language, which is widely used in the underlying development. C language can compile and process low-level memory in a simple way. C language is an efficient programming language, which only produces a small amount of machine language and can run without the support of any running environment. Although C language provides many low-level processing functions.

C language specific content:

For (expression1; Expression 2; Expression 3) Circular body statement.

The expression 1 is an initial value expression, which is used to assign an initial value to the loop variable before the loop starts.

Expression 2 is a loop control logic expression, which controls the conditions of loop execution and determines the number of loops.

Expression 3 is a modified expression of the loop control variable, which makes the for loop tend to end.

The loop body statement is a statement that is repeatedly executed when the loop control condition is established.

However, during the whole process of the for loop, the expression 1 is only evaluated once, while expressions 2 and 3 may be evaluated several times or not at all. The loop body can be executed many times or not at all.