- javascript data type and data structure:
* javascript is a scripting language for the web. like any other programming language . it has its own data types .A data type in a language defines the type of data a variable can hold. javascript has seven types of data which is,
=> Number| String | boolean | Undefined | Null | Object |symbol
2. Try catch block:
* A catch block is where you handle the expectations, this block must follow the try block must follow the try block . A single try block can have several catch blocks associated with it. You can catch block associated with it .we are catch different expectation in different catch block .
3. Javascript Coding Style :
The art of programming is our code must be as clean and easy to read as possible. A good code style greatly assist in that . The beauty of javascript standard style is that its simple .no one wants to maintain multiple hundred line style configuration .all javascript documents must use two spaces for indentation. always use , white space, quotes, variable declaration , naming , comments etc.
4. javascript info /comments:
As we know that comment are started with single line ( // ) or multiline ( /*…… */ ). if you explained what you doing your code its obviously bad coding style . good comment is provide a high-level overview of component, how they interect . a good habit is a good developer is comments their presence and even their absence.good comments allow us to maintain the code well , and use it more effectively.
5. Balancing client and server catching in web development:
Wherever we try to remember our passed things . Then we try to remember it second time but its easy to remember of the first time. it is happen because our brain recalled as soon as first time. Caching works exactly same concept .catching is a method of generally storing the contents of a webpage or an application in locations close to the user like the brain saved the information to our recent memory. their are several types of catching option.like database catching , application catching , distributed catching etc.catching help improving user experience like reduce latency, content availability, avoids network congestion.
6. Javascript Block Bindings :
Variable is more formally known as bindings . when we declare a variable , we actually bind a value to a name inside a scope . scope refers to specific part of a program.so binding occures usually we declare var , let , and const .
* Hoisting : This means the variable and function declarations are put into the memory during the compile phases before going for an execution .
* Block level declaration : if you declare a variable let and const you can not access the declaration out side that block scope .block scope created by the two following places # inside a function # inside a block .
7. Javascript Spread operator:
Spread operator is one of the most powerful features of the ES6 specification . although the rule is simple . Their are different usages of the spread operator and each one target to solve a different problem statement . like as ,
a) Expanding arrays b) Combining arrays
8. Arrow Function:
Their are two benefits to arrow functions. First they are less important than traditional function expression . in javascript traditional function can be used ar, a) Non mated function b) Methods c) Constructor
