Keithley 2657A, Справочное руководство, Страница: 270 / 805

Model 2657A High Power System SourceMeter® Instrument Reference Manual Section 6: Instrument programming
2657A-901-01 Rev. B/December 2012 6-21
While loops
To use conditional expressions to determine whether to execute or end a loop, you use
while
loops.
These loops are similar to Conditional branching (on page 6-19) statements.
while
expression
do
block
end
Where:
•
expression
is Lua code that evaluates to either
true
or
false
•
block
consists of one or more Lua statements
Example: While
list = {
"One", "Two", "Three", "Four", "Five", "Six"}
print("Count list elements on numeric index:")
element = 1
while list[element] do
print(element, list[element])
element = e 1
end This loop exits when
list[element]
= nil
.
Output:
Count list elements on
numeric index:
1.00 One
2.00 Two
3.00 Three
4.00 Four
5.00 Five
6.00 Six
Repeat until loops
To repeat a command, you use the
repeat
...
until
statement. The body of a
repeat
statement
always executes at least once. It stops repeating when the conditions of the
until
clause are met.
repeat
block
until
expression
Where:
•
block
consists of one or more Lua statements
•
expression
is Lua code that evaluates to either
true
or
false
Example: Repeat until
list = {
"One", "Two", "Three", "Four", "Five", "Six"}
print("Count elements in list using repeat:")
element = 1
repeat
print(element, list[element])
element = e 1
until not list[element] Output:
Count elements in list
using repeat:
1.00 One
2.00 Two
3.00 Three
4.00 Four
5.00 Five
6.00 Six