Keyboard
Programming Manual
43
SATO Europe
Loop Statements
Loop statements allow a program to execute one or more lines of code repetitively.
The loop statements that TSKL supports include:
DO…LOOP
FOR…NEXT
WHILE…WEND
DO…[EXITDO]…LOOP
Description
Use a DO loop to execute a block of statements an indefinite number of times. There
are several variations of DO…LOOP statement, but each evaluates a numeric
condition to determine whether or not to continue execution.
Syntax
DO {WHILE | LOOP}
Statements
{EXITDO}
LOOP
Or
DO
Statements
{EXITDO}
LOOP {WHILE | LOOP}
Or
DO
Statements
{EXITDO}
LOOP
Programming Manual Keyboard
SATO Europe
44
Remarks
The total number of DO…LOOP statement in one program cannot exceed 40.
The maximum number of IF…THEN…ELSE, FOR…NEXT, WHILE…WEND, and
DO…LOOP statements available in one program is 40.
Example
A=1
DO WHILE A<10
A=A+1
LOOP
PRINT A
Keyboard
Programming Manual
45
SATO Europe
FOR…[EXITFOR]…NEXT
Description
Executes a series of instructions by a specified number of times in a loop.
(As opposed to DO …LOOP which executes until a condition is met)
Syntax
FOR variable= I TO J [STEP K]
Statements
NEXT variable
Remarks
I, J, K are numeric expressions
I:
the initial value of the counter
J:
the final value of the counter
K:
The increment of the counter. If the K parameter is ignored, the default
increment is 1.
The maximum numbers of IF…THEN…ELSE, FOR…NEXT, WHILE…WEND, and
DO…LOOP statements available in one program is 40.
Example
The following sample program prints out the sum of numbers between 1 and 10:
SUM=0
FOR I=1 TO 10
SUM=SUM+I
NEXT I
PRINT SUM
Programming Manual Keyboard
SATO Europe
46
WHILE…WEND
Description
To execute a series of statements in a loop until the given condition is false.
Syntax
WHILE expression
statements
WEND
Remarks
If the expression is true the program will be executed until the WEND statement is
encountered, then return to the WHILE statement to check again. After encountering a
false condition, the program will branch to the statement following the WEND.
The total numbers of WHILE…WEND statement in one program can not exceed 40.
The maximum numbers of IF…THEN…ELSE, FOR…NEXT, WHILE…WEND, and
DO…LOOP available in one program is up to 40.
Example
A=10
WHILE A
A=A-1
PRINT “12345678”
WEND
Keyboard
Programming Manual
47
SATO Europe
GOTO
Description
Branches from the program to a specified block of statements.
Syntax
GOTO label
Remarks
Label is a tag to mark a specified position in the program.
The Label name is limited to a maximum of 20 characters.
The total number of GOTO statement in a program cannot exceed 200.
Example
INIT:
SUM=0
INDEX=1
INPUT “S/N;”, SN$(INDEX)
IF SN$=”” THEN GOTO INIT
Programming Manual Keyboard
SATO Europe
48
Program-Control Statements
The program-control statements are the essence of any computer language because
they govern the flow of program execution. Program-control statements may be
separated into two categories:
IF…THEN
IF…THEN…ELSE
IF…THEN…ELSE
Description
Use an IF…THEN block to execute one or more statements conditionally. You can use
either a single-line syntax or multiple-line “block” syntax:
Syntax
IF condition THEN statement
Notice that the single-line form of IF…THEN does not use an ENDIF statement.
Or
IF condition THEN
Statements
ENDIF
Or
IF condition THEN
Statements
ELSE
Statements
ENDIF
Keyboard
Programming Manual
49
SATO Europe
Or
IF condition1 THEN
Statement block 1
ELSEIF condition2 THEN
Statement block 2
ELSE
Statement block n
ENDIF
Remarks
If the result of the expression is nonzero, the statement following THEN will be
executed. If the result of the expression is zero, and a statement following the ELSE is
present, it will be executed. Otherwise the next line of statement is executed.
If there are block of statements in IF…THEN …ELSE, ENDIF must be used at the end
of the IF…THEN…ELSE statement.
Limitations:
The total number of IF…THEN…ELSE statements in a program can not exceed 40.
The total numbers of IF…THEN…ELSE, FOR…NEXT, WHILE…WEND, and
DO…LOOP in a program cannot exceed 40.
Example
IF A>0 THEN PRINT “TRUE” ELSE PRINT “FALSE”
IF ANS=1 THEN
CLS
PRINT “Error!!!”
INPUT ANS
ENDIF
10>
Dostları ilə paylaş: |