The Array.indexOf() is an inbuilt TypeScript function which is used to find the index of the first occurrence of the search element provided as the argument to the function.
Syntax:
array.indexOf(searchElement[, fromIndex])
Parameter: This method accepts two parameter as mentioned above and described below:
- searchElement : This parameter is the Element to locate in the array.
- fromIndex : This parameter is the index at which to begin the search.
Return Value: This method returns the index of the found element.
Below examples illustrate the Array indexOf() method in TypeScript.
Example 1:
JavaScript
<script> // Driver code var arr = [ 11, 89, 23, 7, 98 ]; // use of indexOf() method var val = arr.indexOf(7) // printing element console.log(val); </script> |
Output:
3
Example 2:
JavaScript
<script> // Driver code var arr = [ 'a','b','c','a','e' ]; // use of indexOf() method var val = arr.indexOf('a',4) // printing element console.log(val); </script> |
Output:
-1
