Apex Reference Guide
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UUID Class
Contains methods to randomly generate a version 4 universally unique identifier (UUID),
compare UUIDs, and convert UUID instance to a string.
Namespace
Usage
The UUID is generated using a cryptographically strong pseudo-random number generator and is represented as 32 hexadecimal values.
UUID Methods
The following are methods for UUID.
equals(obj)
Compares a UUID instance with the specified object and returns true if both are equal.
Otherwise, returns false.
Signature
public Boolean equals(Object obj)
Parameters
- obj
- Type: Object
- The UUID object to be compared.
Return Value
Type: Boolean
Example
1
2// UUIDs are equal when all the characters in the UUID are the same
3String uuidStr = '707b2538-98bb-41e7-95e3-1d77bf42b102';
4UUID fromStr = UUID.fromString(uuidStr);
5UUID fromStr2 = UUID.fromString(uuidStr);
6Assert.isTrue(fromStr.equals(fromStr2));
7
8// A UUID is never equal to a String or any non-UUID object
9Assert.isFalse(fromStr.equals(uuidStr));
10fromString(str)
Converts a 32 character hexadecimal string representation of a UUID to a UUID
instance.
Signature
public static System.UUID fromString(String str)
Parameters
- str
- Type: String
Return Value
Type: System.UUID
Example
1String uuidStr = '707b2538-98bb-41e7-95e3-1d77bf42b102';
2UUID fromStr = UUID.fromString(uuidStr);
3
4UUID.fromString(null); // Throws NullPointerException
5
6UUID.fromString(‘not a uuid’); // Throws IllegalArgumentException
7hashCode()
Returns the hashcode corresponding to the UUID instance.
Signature
public Integer hashCode()
Return Value
Type: Integer
randomUUID()
A static method that randomly generates a version 4 UUID.
Signature
public static System.UUID randomUUID()
Return Value
Type: System.UUID
A 32 hexadecimal value of the UUID generated.
Example
1UUID randomUUID = UUID.randomUUID();
2system.debug(randomUUID); // Prints the UUID string that was randomly generated
3toString()
Returns the string representation of the UUID instance.
Signature
public String toString()
Return Value
Type: String