Comparison Operators

Comparison operators let your code ask questions about values. Every comparison produces a Boolean result: either true or false. Boolean values drive every decision your code makes, so these six operators are a big step forward.

The Six Comparison Operators

Integer a = 10;
Integer b = 5;

System.debug(a == b); // false - equal to
System.debug(a != b); // true  - not equal to
System.debug(a > b);  // true  - greater than
System.debug(a < b);  // false - less than
System.debug(a >= b); // true  - greater than or equal to
System.debug(a <= b); // false - less than or equal to

Comparisons Produce Boolean Values

Because a comparison is an expression that produces a value, you can store the result in a Boolean variable and use it later:

Integer score = 85;
Boolean isHighScore = score > 80;
System.debug(isHighScore); // true

A Common Trap: = versus ==

A single equals sign = assigns a value to a variable. A double equals sign == compares two values. Mixing them up is one of the most common beginner mistakes, so read your code carefully:

Integer count = 5;           // assignment: count now holds 5
Boolean isFive = count == 5; // comparison: true

More Than Numbers

Comparison operators are not limited to numbers. They also work on text and dates:

String name = 'Ada';
Boolean isAda = name == 'Ada'; // true

Date today = Date.today();
Boolean isEarlier = today < today.addDays(7); // true

Whenever your code needs to make a decision, that decision starts with a comparison.