In this chapter we shed some light onto widely unknown features. Parts like the operator precedence unconsciously are exploited in every-day programming by all of us. Others, like integer variables are easily misused. So, read on and become a Yedi^H^H^H^HScilab master.
The Scilab language protects only twelve words against any modification by the user. These identifiers cannot be used as variables or function names. Any attempt to do so immediately raises an error, which typically reads "incorrect clause".
Table 4-1. Reserved Words
Name | Description |
---|---|
break | Force (premature) exit from a for or while loop |
case | Start clause within a select statement |
do | Synonym for "," after for, while, if, etc. |
else | Start alternative in an if or case statement |
elseif | Add a conditional branch to an if statement |
end | Terminate for, if, select, and while statements |
endfunction | Terminate a function definition |
for | Start a loop with a known number of iterations |
function | Start a function definition |
if | Start a conditional |
select | Start a multi-branch conditional |
then | Synonym for "," after expression in if or select |
Reserved words are protected against abuse by the interpreter, commands which follow in Table 4-2 are not! Some of the commands ought to be reserved words, but they are not. Commands can be used in contexts where variables are valid, however, the results are surprising. Therefore they should not be used as names for variables or functions.
Table 4-2. Commands
Name | Description |
---|---|
abort | Stop current evaluation and return to primary command-level |
apropos word | Search for manual-pages whose synopsis matches word |
clear varname | Remove variable (or function) varname from workspace; see also Section 2.5.3 |
exit | Terminate Scilab sesssion |
help word | Display manual page on topic word |
pause | Switch into pause mode (can be used multiple times) |
pwd | Print the current working directory |
quit | Jump out of pause mode (can be used multiple times) or quit Scilab session |
resume | Stop execution of a function or, in pause mode, return from function |
return | Return from function |
what | List all Scilab reserved words |
while | Start a conditional iteration |
who('local' | 'global') | List local or gobal variables in workspace; see also Section 5.2.1 |
Some uses of do:
for i = 1:n do ..., end while i < n do ..., end if a < b do ..., else ..., end