???????? Dr.Niklaus Wirth ?? 2513

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??????????

• ???????? Dr.Niklaus Wirth ?? 2513
• Pascal ????? Blaise Pascal ???????????????????????
  ?
• ????????????? Algol60 ??? PL/1
• ?????????????????????? (Structured Programming)

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??????????????????????
PROGRAM ???????????
Heading
VAR LABEL CONST TYPE
Declarations
PROCEDURE or FUNCTION
BEGIN
Statements
.
END.
3
?????????????????????????
PROGRAM example(input,output) Calculate
average of three numbers CONST COUNT
3 VAR input1, input2, input3 integer
average real BEGIN readln(input1,input2
,input3) average(input1,input2,input3)/count
writeln(The avarage is,average52) END.
???????
???? ??????
??????????
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????????????????????????????????
??????
Create/Edit Text File
pico ltfilenamegt.pas
Source Code
Machine Code
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???????????(Identifiers)
1. ????????????????????????? A ??? Z
????????????????? 0 ??? 9 ????????????????????
?????? ? ????
2. ????????????????????????????? (??????????????)
??????????? ??????????????? ????????
??????????????? Underline ( _ ) ?????
3. ??????????????? ????????????????????????
4. ????????????????????????????????? 255 ?????????
5. ?????????????????????????????????? (Reserve
Word)
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????????????? (Data Type)

• ???????????????? (Simple-type data)
• ???????????????? (Standard Data Type)
• ??????????????????????? (User-defined Data Type)
• ????????????????????? (Structured-type Data)
• ???????????????? (Pointer-type Data)

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????????????????(Standard Data Type)
1. ????????????????????? (integer) ???? 0 1 -1
-500 44 89
2. ????????????????????? (real) ???? 12.1 0.5 22/7
3. ??????????????? (char) ???? A 2
4. ?????????????? (string) ???? SILPAKORN SC
5. ??????????????????? (boolean) ???? ???? (true)
???? (false)
????????????????? ?????????????????? ???
?????????????????????????????
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???????? (Constants)
??????
????????
CONST PI 3.1415927 TAXRATE 0.07
BLANK MAX True
CONTINUE Press enter to continue..
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?????? (Variables)
??????
????????
VAR radias, high real row, column
integer name string choice
char done boolean
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???????????? (Operators)

• ?????????????????
• ????????? , -, , / , DIV, MOD
• ????????? , -, , /
• ?????????????????
• ??????????????????????? , ltgt, lt, lt, gt, gt
• ?????????????????? AND, OR, NOT

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?????? (Expression)
?????????????? ???????????????? Operand
????????????? ???????? 1 ??????????????
????????????????????????????? ????????????????????
?????????????? Operator
???????????????????
???? ab/cd
???????????????????
???? row gt MAX MAX and Done
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?????????????????????????????
1. ???????????????????????????????
2. ???????????????????????? ??????????????????????
?????????
3. ?????????????????????????????????????
??????
(??????) -(??????) NOT / DIV MOD AND -
OR ltgt lt lt gt gt
??????
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????????
7 10 - 5 MOD 3 4 9 70 - 2
4 9 70 - 8 9
71
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????????
2
1
7
6
5
4
3
8
42
2 ( ( 8 MOD 5 ) ( 4 ( 15 - 3 ) / sqr( -4
2 ) ) )
5 MOD 6
3
8 MOD 5
5
8 DIV 5
1
5 DIV 6
0
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??????????????????????????????

• ??????????????????????????? (arithmetic-logic
  statement)
• ???????????????????????? (input/output statement)
• ??????????????????????????? (selection statement)
• ?????????????? (looping statement)
• ?????????????????????????????? (call subprogram)

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??????????????????????????? (arithmetic-logic
statement)
????????????????? (Assignment Statement)
??? ???????????????????????????????????????????

??????
????????
Price100 tax0.07price
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???????????????????????? (input/output statement)
???????????????????? (Output Statement)
?????????????????????????????????????????????
?????? ?????? Write , Writeln ????????????????????
?????? 2 ????? ???
1. ?????????? ???????? ????????????????
2. ??????????(char)????????????????(string)
??????
write(parameterlengthdecimal,...)
writeln(parameterlengthdecimal,...) writeln
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?????????????????????? (Executable Statements)
??????????????????????? write ??? writeln
?????? writeln ??????????????????????????????????
?????????????????
num1
num2
????????
num110 num220 writeln(Num1 ,
num1) writeln(Num2 , num2)
10
20
10 20
num110 Write(num1102)
Num1 10 Num2 20
10.00
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?????????????????????? (Executable Statements)
??????????????????????? write ??? writeln
????????
num110num220 sumnum1num2 Write(num1,
,num2, ,sum)
10 20 30
Num1num2sum 10 20 30
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????????????????????? 1 ??????????????????????????
????????-????????????

• ???????????????????????????????????????? 2 ???
  ???????
• ?????(Summary)
• ????(Different)
• ?????(Multiply)
• ?????(Devide)
• ???????????? (DIV)
• ??????????? (MOD)
• ???????????????????????

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?????????????????????? (Executable Statements)
????????????????????????? (Input Statement)
????????????????????????????????????????????
(keyboard) ???? ??????????????????????????
?????? ?????? Read , Readln
??????
????????
Read(number) Read(a,b,c)Readln(text)
Readln(x,y,z)
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?????????????????????? (Executable Statements)
??????????????????????? read ??? readln
?????? readln ????????????????????? read ????
readln ???????? ????????????????????????????????(?
????????????????????????????)
????????
Read(number) Read(a,b,c)Readln(text)
Readln(x,y,z)
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????????????????????? 2 ??????????????????????????
????????-????????????
??????????????????????????????????????????????????
? ???????????????????????????????????????????
???????????????