Basic syntax

Here is the basic syntax for an "if" statement:

if (condition) {
  // code to be executed if the condition is true
}

Here is the syntax for an "if" statement with an "else" clause:

if (condition) {
  // code to be executed if condition is true
} else {
  // code to be executed if condition is false
}

The condition is a boolean expression that evaluates to either true or false. If the condition is true, the code in the "if" block is executed. If the condition is false, the code in the "else" block is executed (if present).

Examples

Here are some examples of using "if" and "else" statements in JavaScript:

let x = 10;

if (x > 5) {
  console.log("x is greater than 5");
} else {
  console.log("x is not greater than 5");
}

In this example, the condition x > 5 evaluates to true, so the code in the "if" block is executed, and the output is:

x is greater than 5

Here is another example:

let y = 3;
if (y % 2 === 0) {
  console.log("y is even");
} else {
  console.log("y is odd");
}

In this example, the condition y % 2 === 0 evaluates to false, so the code in the "else" block is executed, and the output is:

y is odd

Conclusion

• The "if" statement in JavaScript is used to execute a block of code if a certain condition is met.
• The "else" clause is used to execute a block of code if the condition is not met.
• The condition is a boolean expression that evaluates to either true or false.
• The "if" statement can be followed by an "else" clause to handle the case when the condition is false.