Job 4 Summary

1. Knowledge Points:

(1) Character type

Char ch;

(Ch >= ' a ' && ch <= ' z ') | | (Ch >= ' A ' && ch <= ' Z ')

(Ch >= ' 0 ' && ch <= ' 9 ')

• Character type data

Character variable: char ch; (defines the character variable ch for storing character data.) ）

Character constant: ' A ' z ' ' a ' z ' 0 ' 9 ' \ n ' (2) input and output of character data • Character input function GetChar

Enter a character

Char ch;

ch = getchar ();

• Character output function Putchar

Output one character

Putchar (output parameter); (3) Logical operation

(Ch >= ' a ' && ch <= ' z ') | | (Ch >= ' A ' && ch <= ' Z ')

Ch >= ' 0 ' && ch <= ' 9 '

• Logical operators: &&;| | ；！ ；

• Logical expression: A formula that connects a logical operand with a logical operator.

(4) Else–if statement

if (expression 1) Statement 1

else if (expression 2) Statement 2

else if (expression n-1) statement n-1

Else Statement n

(5) Switch statement

Handles multi-branch selection issues in 3 scenarios:

① use the break statement in each statement segment of the switch statement

switch (expression) {

case constant Expression 1: statement segment 1; Break

Case constant Expression 2: statement segment 2; Break

.......

case constant Expression N: statement segment n; Break

Default: statement segment n+1; Break

}

② do not use break in switch

switch (expression) {

case constant Expression 1: statement segment 1;

Case constant Expression 2: statement segment 2;

.......

case constant Expression N: statement segment n;

Default: statement segment n+1;

}

③ using break in certain statement segments of switch

• General form:

switch (expression)

{Case constant-expression 1: statement 1

Case constant Expression 2: statement 2

case constant Expression N: statement n

Default: Statement n+1

}

Job 4 Summary