1. Control Flow
You should know the following control statements:
2. Exception Handling or Error Handling
You must know that how you should catch an error and display it to the user. It does not matter whether you are a front-end-developer or back-end-developer. You may find these in control. error log or control.log.
3. Be Careful while using operators
You need to be careful while you are using a type of which is a unary operator which is used to return a string value.
Then one should know the proper use of constructors as this internal property could be overridden.
4. Knowledge of Architecture
5. Database Models
Till is very important to know whether there is a need to group-specific information pieces at a particular place or they are good to go separately. This applies to not only data models but also to objects and variables.
6. Knowing about DOM Manipulation
7. Good to know Node
8. Use of functions
9. Process use of Regular Expressions