Control Flow & Logic in Apex
Conditional Statements: if / else, switch
What Are Conditional Statements?
Conditional statements allow Apex to make decisions based on conditions.
Simple Explanation
“If this condition is true, do this. Otherwise, do something else.”
if / else Statement
Real-Life Example
If your bank balance is enough → you can buy a product.
Otherwise → you cannot.
Code Example
Integer balance = 500;
if (balance >= 300) {
System.debug('Purchase allowed');
} else {
System.debug('Insufficient balance');
}
switch Statement
When to Use switch
Use switch when you have multiple fixed conditions.
Real-Life Example
Different customer types get different discounts.
Code Example
String customerType = 'Gold';
switch on customerType {
when 'Gold' {
System.debug('20% discount');
}
when 'Silver' {
System.debug('10% discount');
}
when else {
System.debug('No discount');
}
}
Gist (Quick Revision)
-
if / else→ best for simple decisions -
switch→ best for multiple known values
Loops: for / while / do-while
What Are Loops?
Loops allow Apex to repeat actions until a condition is met.
Simple Explanation
Loops save time by doing the same task again and again automatically.
for Loop
Real-Life Example
Send emails to all customers in a list.
Code Example
for (Integer i = 1; i <= 3; i++) {
System.debug('Email sent ' + i);
}
while Loop
When to Use
Use while when you don’t know in advance how many times the loop will run.
Code Example
Integer count = 1;
while (count <= 3) {
System.debug('Count is ' + count);
count++;
}
do-while Loop
Key Difference
do-while runs at least once, even if the condition is false.
Code Example
Integer number = 5;
do {
System.debug('This runs at least once');
} while (number < 3);
Gist (Quick Revision)
-
for→ known number of repetitions -
while→ unknown repetitions -
do-while→ must run at least once
Loop Control Statements: break & continue
What Is break?
break stops the loop completely.
Real-Life Example
Stop searching once you find the item.
Code Example
for (Integer i = 1; i <= 5; i++) {
if (i == 3) {
break;
}
System.debug(i);
}
What Is continue?
continue skips the current iteration and moves to the next one.
Real-Life Example
Skip weekends when counting working days.
Code Example
for (Integer i = 1; i <= 5; i++) {
if (i == 3) {
continue;
}
System.debug(i);
}
Gist (Quick Revision)
-
break→ stop loop entirely -
continue→ skip current step
