if (comparison) { instructions... }

else { instructions... }

If the comparison between the round brackets is true (i.e. evaluates to non-zero), all instructions between the first pair of winged brackets are executed. It it's not true (i.e. evaluates to zero), the instructions between the second pair of winged brackets following else will be executed. The else part with the second set of instructions can be omitted.  LC  In lite-C, C, or C++, the winged brackets can be omitted when only one instruction is to be executed dependent on the comparison.

Speed:

Fast

Remarks:

In C/C++, comparisons are early aborted when a && is encountered and the expression left of it evaluates to false, or when a || is encountered and the expression left of it evaluates to true. Lite-C does not early abort expressions. This requires a slightly different syntax for checking the value of a struct pointer and its element in the same expression: 
if ((ptr != NULL) && (ptr->element == ..)) // C/C++
if (ptr != NULL) if (ptr->element == ..) // lite-C

Example:

if (((x+3)<9) || (y==0))   // set z to 10 if x+3 is below 9, or if y is equal to 0
{
	z = 10;
}
else    
{
	z = 5;// set z to 5 in all other cases
}

See also:

comparisions, while ► latest version online