How to use if else in js

JavaScript’s if else statement is used to execute a code block based on conditions. The syntax is: if (condition) {code block} else {code block}. It can be nested to create complex branching logic. Conditions can evaluate to boolean values, else statements are optional, and additional branch conditions can be added using else if statements.

Usage of if else statement in JavaScript

The if else statement is used in JavaScript to control the code execution flow Conditional statements. It allows code to execute different blocks based on specified conditions.

Syntax:

<code>if (条件) {
  // 如果条件为真，则执行的代码块
} else {
  // 如果条件为假，则执行的代码块
}</code>

Usage:

1. Set conditions: Inside if statement The condition is a Boolean value that determines whether a block of code is executed.
2. Execute code block: If the condition is true, execute the if code block. If the condition is false, the else block is executed.
3. Nested if else statements: if else statements can be nested to create complex branching logic.

Example:

<code>// 检查变量是否大于 10
if (num > 10) {
  // 如果条件为真，则执行此代码块
  console.log("变量大于 10");
} else {
  // 如果条件为假，则执行此代码块
  console.log("变量小于或等于 10");
}</code>

Other notes:

• The condition can be anything that can evaluate to Boolean expression.
• else statement is optional. If there is no else statement, no code will be executed if the condition is false.
• Additional branch conditions can be added using the else if statement.

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