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JS Syntax

JavaScript (JS) is a programming language that is used to create interactive and dynamic web pages. It is a client-side scripting language that is executed by web browsers. JS syntax is the set of rules that govern how JS code is written and structured. Understanding JS syntax is essential for writing efficient and effective code.

Brief Explanation of JS Syntax

JS syntax is similar to other programming languages such as Java and C++. It consists of a set of rules that define how code should be written and structured. The syntax includes keywords, variables, operators, functions, and statements.

Keywords are reserved words that have a specific meaning in JS. They cannot be used as variable names or function names. Examples of keywords include var, if, else, for, and while.

Variables are used to store data values. They are declared using the var keyword followed by the variable name. Variables can hold different types of data such as numbers, strings, and boolean values.

Operators are used to perform operations on variables and values. Examples of operators include arithmetic operators such as +, -, *, and /, comparison operators such as ==, !=, <, and >, and logical operators such as && and ||.

Functions are blocks of code that perform a specific task. They are declared using the function keyword followed by the function name and parameters. Functions can be called multiple times and can return a value.

Statements are used to control the flow of the program. Examples of statements include if statements, for loops, and while loops. Statements are executed in the order in which they appear in the code.

Code Examples

Here are some examples of JS syntax:

<script>
  // declaring a variable
  var x = 5;

  // performing arithmetic operations
  var y = x + 3;
  var z = x * y;

  // using if statement
  if (z > 20) {
    document.write("z is greater than 20");
  } else {
    document.write("z is less than or equal to 20");
  }

  // declaring a function
  function greet(name) {
    document.write("Hello, " + name + "!");
  }

  // calling a function
  greet("John");

</script>

In this example, we declare a variable x and assign it the value of 5. We then perform arithmetic operations on x to get the values of y and z. We use an if statement to check if z is greater than 20 and display a message accordingly. We also declare a function greet that takes a parameter name and displays a greeting message. We call the greet function and pass it the value "John".

Conclusion

JS syntax is the set of rules that govern how JS code is written and structured. Understanding JS syntax is essential for writing efficient and effective code. By following the rules of JS syntax, you can create interactive and dynamic web pages that provide a great user experience.

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