C Language: comma operator

The comma operator is primarily used for connection expressions

Example: a=1+2,b=3*4

An expression concatenated with the comma operator is called a comma-expression.

The general form of it is:
Expression 1, expression 2, ..., expression n
The operation of the comma expression is: first evaluates the expression 1, then evaluates the expression 2, then calculates to the expression n

The value of the entire comma-expression is the value of the last expression

C Language: comma operator