Why Control Statements Matter

Without control statements:
● Code would always execute line by line
● No decision making would be possible
● No bulk processing could happen

Control statements make your code:
● Dynamic
● Flexible
● Scalable

if–else Statement

Used to execute logic based on a condition.

Example:

Integer score = 75;

if(score >= 60) {
    System.debug('Passed');
} else {
    System.debug('Failed');
}

Use when:
● Simple conditional logic
● Two or more decision paths

else-if Ladder

Used when multiple conditions exist.

Example:

Integer marks = 85;

if(marks >= 90) {
    System.debug('Grade A');
} 
else if(marks >= 75) {
    System.debug('Grade B');
} 
else {
    System.debug('Grade C');
}

switch Statement

Used when a variable can have multiple fixed values.

Example:

String status = 'NEW';

switch on status {
    when 'NEW' {
        System.debug('Order created');
    }
    when 'PROCESSING' {
        System.debug('Order in progress');
    }
    when 'COMPLETED' {
        System.debug('Order finished');
    }
    when else {
        System.debug('Unknown status');
    }
}

Use when:
● Multiple fixed conditions
● Cleaner than long if-else chains

for Loop

Used to repeat logic multiple times.

◆ Standard for Loop

for(Integer i = 0; i < 5; i++) {
    System.debug('Value: ' + i);
}

◆ Enhanced for Loop (Collection)

List<String> names = new List<String>{'Amit','Rahul','Neha'};

for(String name : names) {
    System.debug(name);
}

Use when:
● Iterating collections
● Bulk processing

while Loop

Executes until condition becomes false.

Example:

Integer count = 0;

while(count < 3) {
    System.debug(count);
    count++;
}

Use carefully to avoid infinite loops.

break and continue

◆ break

Stops loop execution.

for(Integer i = 1; i <= 5; i++) {
    if(i == 3) {
        break;
    }
    System.debug(i);
}

◆ continue

Skips current iteration.

for(Integer i = 1; i <= 5; i++) {
    if(i == 3) {
        continue;
    }
    System.debug(i);
}

Real-World Example – Filtering Records

List<Account> activeAccounts = new List<Account>();

for(Account acc : [SELECT Id, Name, Active__c FROM Account]) {
    if(acc.Active__c == true) {
        activeAccounts.add(acc);
    }
}

Common Pitfalls

● Infinite loops due to missing exit condition

● Complex nested if statements
● SOQL inside loops
● Missing null checks

Productivity Tips

● Prefer switch over long if-else chains

● Keep conditions readable
● Avoid deep nesting
● Bulkify loops

Conclusion

You now understand:
● Conditional execution

● Looping mechanisms
● Execution control
● Real-world filtering logic

Happy Coding! 🚀

Apex Beginner to Advance

Control Statements in Apex