How to get the key prefix of an Object in Salesforce

How to get the key prefix of an Object in Salesforce

We know there are two types of record-id are present in Salesforce.

• 15 digit -- Case Sensitive
• 18 digit -- Case Insensitive

Only 3 digits of ids represent object type.

For example :- 

• Account - 001
• Note      - 002
• Contact - 003
• Opportunities - 006
• Lead  - 00Q

Q: How will get these prefix dynamically, I mean by using Apex code?

Ans: Schema.DescribeSObjectResult r = CustomObject__c.sObjectType.getDescribe();String keyPrefix = r.getKeyPrefix();System.debug('***ObjectKeyPrefix***'+keyPrefix );

It will print prefix of Custom Object id.

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