what are logical operators in js

Logical operators in JS

Logical operators are used to combine two or more Boolean values ​​(true/false) to generate a new Boolean value. In JavaScript, there are the following three logical operators:

1. and (&&)
2. or (||)
3. Not (!)

1. And (&&)

• ## means: It is true only if it is true at the same time
• Usage: Connect multiple Boolean values. If all Boolean values ​​are true, the result is true; otherwise, it is false.

• Example:

  <code class="js">const isLoggedIn = true;
  const hasAccess = true;
  
  const canAccess = isLoggedIn && hasAccess; // true</code>

2. Or (||)

• means: It is true only if at least one is true
• Usage: Connect multiple Boolean values. If any Boolean value is true, then the result is true; otherwise, it is false.

• Example:

  <code class="js">const isMember = false;
  const isFriend = true;
  
  const canJoin = isMember || isFriend; // true</code>

3. Not(!)

• means: Negate, change true to false, change false to true
• Usage: Operate on a Boolean value and negate its value.

• Example:

  <code class="js">const isNight = false;
  
  const isDay = !isNight; // true</code>

Usage scenarios

Logical operators in JavaScript Widely used in:

Conditional statements (if-else)
• Loop control
• Data validation
• Construct complex logical expressions

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