The $.isArray() method in jQuery is used to determine whether a given value is an array. It is part of jQuery's utility functions designed to provide type checking and other common tasks.

Syntax

$.isArray(value);

• value: The value you want to check.

Description

The $.isArray() method checks if the provided value is an array. It returns true if the value is an array and false otherwise.

Example Usage

Here are some examples illustrating how to use $.isArray():

Basic Example

var fruits = ["Apple", "Banana", "Cherry"];
var number = 42;

console.log($.isArray(fruits)); // true
console.log($.isArray(number)); // false

• Explanation:
  • $.isArray(fruits) returns true because fruits is an array.
  • $.isArray(number) returns false because number is not an array.

Checking with Different Types

console.log($.isArray([])); // true
console.log($.isArray({})); // false
console.log($.isArray("string")); // false
console.log($.isArray(null)); // false
console.log($.isArray(undefined)); // false

• Explanation:
  • $.isArray([]) returns true because it's an empty array.
  • $.isArray({}) returns false because it's an object, not an array.
  • $.isArray("string") returns false because it's a string.
  • $.isArray(null) and $.isArray(undefined) both return false because neither null nor undefined are arrays.

Practical Use Case

The $.isArray() method is useful when you need to validate whether a variable is an array before performing array-specific operations, such as iteration or array methods.

Example: Validating Input

function processItems(items) {
  if ($.isArray(items)) {
    $.each(items, function(index, item) {
      console.log("Item " + index + ": " + item);
    });
  } else {
    console.log("Input is not an array");
  }
}

processItems(["Apple", "Banana", "Cherry"]); // Processes items
processItems("Not an array"); // Logs "Input is not an array"

• Explanation:
  • processItems() checks if items is an array. If it is, it processes the items; otherwise, it logs an error message.