Comparison operators in JavaScript are used to compare values and return a boolean result (true or false). These operators help in making decisions based on conditions. Here’s a detailed look at each comparison operator:

1. Equality (==)

• Purpose: Checks if two values are equal, performing type coercion if necessary.
• Example:

  let a = 5;
  let b = '5';
  console.log(a == b); // true, because '5' is coerced to a number
  

2. Strict Equality (===)

• Purpose: Checks if two values are equal without performing type coercion.
• Example:

  let a = 5;
  let b = '5';
  console.log(a === b); // false, because the types are different
  

3. Inequality (!=)

• Purpose: Checks if two values are not equal, performing type coercion if necessary.
• Example:

  let a = 5;
  let b = '5';
  console.log(a != b); // false, because '5' is coerced to a number
  

4. Strict Inequality (!==)

• Purpose: Checks if two values are not equal without performing type coercion.
• Example:

  let a = 5;
  let b = '5';
  console.log(a !== b); // true, because the types are different
  

5. Greater Than (>)

• Purpose: Checks if the value on the left is greater than the value on the right.
• Example:

  let a = 10;
  let b = 5;
  console.log(a > b); // true
  

6. Less Than (<)

• Purpose: Checks if the value on the left is less than the value on the right.
• Example:

  let a = 3;
  let b = 7;
  console.log(a < b); // true
  

7. Greater Than or Equal To (>=)

• Purpose: Checks if the value on the left is greater than or equal to the value on the right.
• Example:

  let a = 5;
  let b = 5;
  console.log(a >= b); // true
  

8. Less Than or Equal To (<=)

• Purpose: Checks if the value on the left is less than or equal to the value on the right.
• Example:

  let a = 4;
  let b = 5;
  console.log(a <= b); // true
  

Key Points:

• Type Coercion: With == and !=, JavaScript performs type coercion, meaning it tries to convert and compare values. For instance, 0 == false is true because false is coerced to 0.
• Strict Comparison: === and !== do not perform type coercion. They check both value and type. For example, 0 === false is false because they are of different types.
• NaN Comparisons: NaN is not equal to any value, including itself. So, NaN === NaN is false. Use Number.isNaN() to check for NaN.