The Developer’s Guide to the Force.com Platform

For Loops

Apex support three types of For loops: traditional, list/set iteration, and SOQL.

The traditional For loop uses the following syntax:

for (init_statement; exit_condition; increment_statement) {
 code_block;
 }

The init_statement executes when the loop is first entered and can initialize more than one variable. The exit_condition is evaluated every time the loop executes. If the condition evaluates to false, the loop ends. If the condition evaluates to true, the code_block executes, followed by the increment statement.

A typical For loop of this variety is as follows:

for (Integer I = 0; I < 10 ; I++) {
 System.debug('Iteration ' + I);
 }

This loop prints a list to the debug console consisting of the word Iteration followed by the values ...