Basic Statement of C language

1 Basic form if (expression) statement

The semantics are: if the expression is true, the subsequent statement is executed, and if the expression is false, the statement is not executed.

Example 1 compares two integers, max is the maximum number.

1 void Main () 2 {  3   int  4  5   max=A; 6 7  if (max<B) 8 {  9    max=b; Ten } one}

2 If ... else form.

if(expression) {statement 1;} Else statement 2;

If the expression is true, execute statement 1, and if it is not true, execute statement 2

Example 2 compares two integers, max of which is the maximum number, and use the If.....else statement to discriminate the size of a/b.

void Main () {     int'    if(a>b) {  =A;} Else {   =b;}}

3 switch-case statement.

switch (expression)

{

case constant Expression 1: statement 1;

Case constant Expression 2: statement 2;

Case constant Expression 3: statement 3;

Default: Statement n+1;

}

Evaluates the value of an expression and compares it to the value of the constant expression thereafter, when the value of the expression is equal to the value of a constant expression, that is, executes the subsequent statement, and then ceases to judge, and proceeds to the statement following all the subsequent case;

When the value of an expression is not equal to the constant expression following all of the case, the statement after the default is executed.

Example 4 Switch Statement instance

#include <stdio.h>voidMain0{   Chardat; Day=3; Switch(DAT) { Case 0:p rintf ("sun\t");  Case 1:p rintf ("mon\t");  Case 2:p rintf ("tues\t");  Case 3:p rintf ("wed\t");  Case 4:p rintf ("thurs\t");  Case 5:p rintf ("fri\t");  Case 6:p rintf ("satur\t"); defualt:printf ("This is a worng number\n");}}

The result of the operation is Wed Thurs Fri Satur

Basic Statement of C language