Section 6: Instrument programming Model 2651A High Power System SourceMeter® Instrument Reference Manual
6-26 2651A-901-01 Rev. A / March 2011
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 = element + 1
end
This loop will exit when
list[element] = nil.
Output:
Count list elements on
numeric index:
1.000000000e+00 One
2.000000000e+00 Two
3.000000000e+00 Three
4.000000000e+00 Four
5.000000000e+00 Five
6.000000000e+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 = element + 1
until not list[element]
Output:
Count elements in list
using repeat:
1.000000000e+00 One
2.000000000e+00 Two
3.000000000e+00 Three
4.000000000e+00 Four
5.000000000e+00 Five
6.000000000e+00 Six
For loops
There are two variations of for statements supported in Lua: numeric and generic.
NOTE
In a for loop, the loop expressions are evaluated once, before the loop starts.