What's statement and expression in JavaScript ?

Let's talk about the concepts of statements and expressions in JavaScript. These two things are fundamental to writing code in JavaScript, and they might seem a little confusing at first, but don't worry, I've got you covered.

So, what are statements in JavaScript? Think of statements like instructions that the computer follows in order. Each statement is a separate line of code that performs a specific action or task. For example, you might write a statement that tells the computer to display a message on the screen, or a statement that tells the computer to perform a calculation.

Now, let's take a look at some examples of statements in JavaScript. One common statement you'll use is the if statement. This statement allows you to test a condition and execute a block of code if that condition is true. Here's an example:

if (age >= 18) {
  console.log("You're old enough to vote!");
}

In this statement, we're checking if the age variable is greater than or equal to 18. If it is, we print a message to the console.

Another type of statement is the for loop. This statement is used to iterate over a block of code a certain number of times. Here's an example:

for (let i = 1; i <= 5; i++) {
  console.log(i);
}

In this statement, we're using a for loop to print the numbers 1 through 5 to the console.

Now, let's move on to expressions. An expression is something that evaluates to a value. Think of it like a math problem - you have an equation on one side of the equal sign, and the answer on the other side. In JavaScript, expressions can be made up of variables, operators, and function calls.

Let's take a look at some examples of expressions. One common type of expression is an arithmetic expression. This is an expression that performs a mathematical operation, like addition or subtraction. Here's an example:

const sum = 2 + 2;
console.log(sum);

In this expression, we're adding the numbers 2 and 2 together, and assigning the result to the sum variable. Then we're printing that value to the console.

Another type of expression is a string expression. This is an expression that represents textual data. Here's an example:

const message = "Hello, friend!";
console.log(message);

In this expression, we're assigning the string "Hello, friend!" to the message variable, and then printing it to the console.

So, to sum up, statements and expressions are both important concepts in JavaScript programming. Statements are like instructions that the computer follows in order, while expressions are like math problems that evaluate to a value. By understanding these concepts, you'll be well on your way to writing effective and efficient JavaScript code.