How do you use findIndex in array of objects?

How do you use findIndex in array of objects?

Definition and Usage The findIndex() method executes a function for each array element. The findIndex() method returns the index (position) of the first element that passes a test. The findIndex() method returns -1 if no match is found. The findIndex() method does not execute the function for empty array elements.

How do you use indexOf in array of objects in Java?

public int indexOf(Object o) The indexOf() method is used to get the index of the first occurrence of an element in an ArrayList object. The element whose index is to be returned. Return Value: The index of the first occurrence an element in ArrayList, or -1 if the element does not exist.

How do you find the index of an object in an array in TypeScript?

TypeScript – Array indexOf() indexOf() method returns the first index at which a given element can be found in the array, or -1 if it is not present.

How do I find the index of an object?

To find the index of an object in an array, by a specific property:

  1. Use the map() method to iterate over the array, returning only the value of the relevant property.
  2. Call the indexOf() method on the returned from map array.
  3. The indexOf method returns the index of the first occurrence of a value in an array.

Does indexOf work on arrays?

indexOf() The indexOf() method returns the first index at which a given element can be found in the array, or -1 if it is not present.

What does indexOf find?

indexOf() The indexOf() method, given one argument: a substring to search for, searches the entire calling string, and returns the index of the first occurrence of the specified substring.

How do you find the index of an element in a string?

5 Ways to Find the Index of a Substring in Strings in Python

  1. str.find()
  2. str.rfind()
  3. str.index()
  4. str.rindex()
  5. re.search()

Is indexOf faster?

It seems in large arrays indexOf may be a faster choice. EDIT: Based on more tests, indexOf seems to run faster than a for loop in the version of Safari I’m using (5.0. 3) and slower in just about everything else.

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