JavaScript String indexOf () Method - W3Schools
Description The indexOf () method returns the position of the first occurrence of a value in a string. The indexOf () method returns -1 …
Array.prototype.indexOf () - JavaScript | MDN - MDN Web Docs
Oct 26, 2026 · The indexOf () method of Array instances returns the first index at which a given element can be found in the array, or …
String.IndexOf Method (System) | Microsoft Learn
The following example uses the IndexOf method to determine the starting position of an animal name in a sentence. It then uses this …
String.prototype.indexOf () - JavaScript - MDN
Jul 10, 2025 · The indexOf () method of String values searches this string and returns the index of the first occurrence of the …
JavaScript Array indexOf () Method - W3Schools
The indexOf () method starts at a specified index and searches from left to right (from the given start postion to the end of the array). …
JavaScript String indexOf () Method
The indexOf () returns the index of the first occurrence of a substring in a string, or -1 if the string does not contain the substring. The …
javascript - indexOf () > -1 vs indexOf () != -1 - Stack Overflow
Dec 20, 2017 · The use of -1 is because the indexOf operation will return -1 in the event the searched for value does not exist in the …
JavaScript String indexOf () Method - Online Tutorials Library
The JavaScript String indexOf () method is used to find the index of the first occurrence of the specified substring in the original …
Exploring the indexOf Method for Strings and Arrays in JavaScript
Dec 16, 2019 · An overview of how the indexOf () method works to find the position of a substring in a string or an item in an array in …
List<T>.IndexOf Method (System.Collections.Generic)
IndexOf (T, Int32) Searches for the specified object and returns the zero-based index of the first occurrence within the range of …