if

Test the value of a condition, and if true, execute a statement block.

if <bool:condition>
  ... statement block ...
endif

int i
set i 5


if <islt i 0>
  echo "negative number"
elseif <iseq i 0>
  echo "zero"
else
  echo "positive number"
endif

If statements in ZeoScript will conditionally execute a block of code that is explicitly terminated by an elsif, else or endif statement.

Each if statement must be closed by a single matching endif statement. Optionally, the if statement may be followed by multiple elseif statements, and/or one else statement. The else statement must be the final conditional statement before the terminating endif statement.

ZeoScript differs from C/C++ and some other programming languages in that if, else and elseif statements are explicitly block statements. In C/C++, for instance, you can omit the block { parens } after an if statement if you only want the next statement to be executed. Not so in ZeoScript; all if, else and elseif statements must be explicitly closed.

Wrong:

if <islt i 0>
  echo "negative number"
else                  // error, else not terminated by endif
if <iseq i 0>
  echo "zero"
else
  echo "positive number"
endif

This code will result in the following error:

ZeoScript error: Cannot find matching 'endif' for 'else' statement.
 - Line 3: 'else'

ZeoScript compilation aborted on line 3 following errors.

Right:

if <islt i 0>
  echo "negative number"
else                  // now the else is terminated by 'endif', and contents are nested
  if <iseq i 0>
    echo "zero"
  else
    echo "positive number"
  endif
endif

Better:

if <islt i 0>
  echo "negative number"
elseif <iseq i 0>            // using the elseif statement, rather than nested else/if
  echo "zero"
else
  echo "positive number"
endif

• elseif
• else
• endif