How to use includes with push in js

The includes() and push() methods are used together in JavaScript to implement array element checking and dynamic updating. The includes() method returns whether the specified element is present in the array, while the push() method adds a new element to the end of the array. Clever combinations can be used to avoid duplicates, update arrays dynamically, or create new arrays without duplicates.

How to use the includes() and push() methods together

In JavaScript, includes The () method is used to check whether an array contains an element, while the push() method is used to add a new element to the end of the array. Cleverly combining these two methods, developers can effectively manipulate and manage arrays.

Function Description

• Check whether an element is in the array: includes() The method returns a Boolean value, indicating whether The specified element exists.
• Add elements to the end of the array: push() method adds one or more new elements to the end of the array.

Using in combination

To combine the includes() and push() methods, use Following steps:

1. Use includes() method to check if an array contains an element.
2. If the element does not exist, use the push() method to push the element into the array.

Example

const arr = ['apple', 'banana', 'orange'];

// 检查数组中是否包含 "grape"
if (!arr.includes('grape')) {
  // 如果没有 "grape"，则将其推入数组
  arr.push('grape');
}

console.log(arr); // 输出：['apple', 'banana', 'orange', 'grape']

Common usage

• Prevent duplicates: Before adding a new element to the array, use includes() to check if the array already contains the element. If included, the addition operation is ignored.
• Dynamic update of the array: When responding to user input or other conditions, you can use includes() and push() to dynamically update the array. content.
• Array deduplication: You can use includes() and push() to create a new array that does not contain duplicates.

Extra Tips

• includes() The method is case-sensitive.
• If you want to push multiple elements to the end of the array, you can use the spread operator (...) to merge them with the original array.

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