- JavaScript Basics
- JavaScript Tutorial
- JavaScript: where to write
- JavaScript: how to display
- JavaScript: keywords
- JavaScript: comments
- JavaScript: variables
- JavaScript: operators
- JavaScript: data types
- JavaScript Conditional Statements
- JavaScript: if-else
- JavaScript: switch
- JavaScript: for loop
- JavaScript: while loop
- JavaScript: do-while loop
- JavaScript: break and continue
- JavaScript Popup Boxes
- JavaScript: alert box
- JavaScript: confirm box
- JavaScript: prompt box
- JavaScript Popular Topics
- JavaScript: functions
- JavaScript: innerHTML
- JavaScript: getElementById()
- JavaScript: getElementsByClassName()
- JavaScript: getElementsByName()
- JavaScript: getElementsByTagName()
- JavaScript: querySelector()
- JavaScript: querySelectorAll()
- JavaScript: document.write()
- JavaScript: console.log()
- JavaScript: boolean
- JavaScript: events
- JavaScript: Math object
- JavaScript: Math.random()
- JavaScript: Number()
- JavaScript: parseInt()
- JavaScript: parseFloat()
- JavaScript Arrays
- JavaScript: array
- JavaScript: find length of array
- JavaScript: add element at beginning
- JavaScript: add element at end
- JavaScript: remove first element
- JavaScript: remove last element
- JavaScript: get first index
- JavaScript: get last index
- JavaScript: reverse an array
- JavaScript: sort an array
- JavaScript: concatenate arrays
- JavaScript: join()
- JavaScript: toString()
- JavaScript: from()
- JavaScript: check if value exists
- JavaScript: check if array
- JavaScript: slice an array
- JavaScript: splice()
- JavaScript: find()
- JavaScript: findIndex()
- JavaScript: entries()
- JavaScript: every()
- JavaScript: fill()
- JavaScript: filter()
- JavaScript: forEach()
- JavaScript: map()
- JavaScript Strings
- JavaScript: string
- JavaScript: length of string
- JavaScript: convert to lowercase
- JavaScript: convert to uppercase
- JavaScript: string concatenation
- JavaScript: search()
- JavaScript: indexOf()
- JavaScript: search() vs. indexOf()
- JavaScript: match()
- JavaScript: match() vs. search()
- JavaScript: replace()
- JavaScript: toString()
- JavaScript: String()
- JavaScript: includes()
- JavaScript: substr()
- JavaScript: slice string
- JavaScript: charAt()
- JavaScript: repeat()
- JavaScript: split()
- JavaScript: charCodeAt()
- JavaScript: fromCharCode()
- JavaScript: startsWith()
- JavaScript: endsWith()
- JavaScript: trim()
- JavaScript: lastIndexOf()
- JavaScript Date and Time
- JavaScript: date and time
- JavaScript: Date()
- JavaScript: getFullYear()
- JavaScript: getMonth()
- JavaScript: getDate()
- JavaScript: getDay()
- JavaScript: getHours()
- JavaScript: getMinutes()
- JavaScript: getSeconds()
- JavaScript: getMilliseconds()
- JavaScript: getTime()
- JavaScript: getUTCFullYear()
- JavaScript: getUTCMonth()
- JavaScript: getUTCDate()
- JavaScript: getUTCDay()
- JavaScript: getUTCHours()
- JavaScript: getUTCMinutes()
- JavaScript: getUTCSeconds()
- JavaScript: getUTCMilliseconds()
- JavaScript: toDateString()
- JavaScript: toLocaleDateString()
- JavaScript: toLocaleTimeString()
- JavaScript: toLocaleString()
- JavaScript: toUTCString()
- JavaScript: getTimezoneOffset()
- JavaScript: toISOString()
- JavaScript Regular Expression
- JavaScript: regular expression
- JavaScript: RegEx . (dot)
- JavaScript: RegEx \w and \W
- JavaScript: RegEx \d and \D
- JavaScript: RegEx \s and \S
- JavaScript: RegEx \b and \B
- JavaScript: RegEx \0
- JavaScript: RegEx \n
- JavaScript: RegEx \xxx
- JavaScript: RegEx \xdd
- JavaScript: RegEx quantifiers
- JavaScript: RegEx test()
- JavaScript: RegEx lastIndex
- JavaScript: RegEx source
- JavaScript Programs
- JavaScript Programs
JavaScript lastIndexOf(): Get the Last Index of an Element
The JavaScript lastIndexOf() method returns the last index of a specified element in a specified array. For example:
<!DOCTYPE html>
<html>
<body>
<p id="xyz"></p>
<script>
const cities = ["Tokyo", "Los Angeles", "Bangkok", "Dubai", "Los Angeles", "Berlin"];
let x = cities.lastIndexOf("Los Angeles");
document.getElementById("xyz").innerHTML = x;
</script>
</body>
</html>In the above example, the following JavaScript statement:
let x = cities.lastIndexOf("Los Angeles");
states that the index number of the last Los Angeles from the array named cities will initialize a variable named x.
Note: Indexing always starts with 0. Therefore, Tokyo is at index number 0. Similarly, the first Los Angeles is at index number 1, and the last Los Angeles is at index number 4.
JavaScript lastIndexOf() syntax
The syntax of the lastIndexOf() method in JavaScript is:
array.lastIndexOf(item, start)
Note: The item parameter is required and is used to specify the value that has to be searched in the array.
Note: The start parameter is optional and is used to specify where to start the search. The default value of this parameter is the index of the last element that is array.length-1.
Note: The lastIndexOf() method returns -1 if the specified value does not exist in the given array.
JavaScript lastIndexOf() example
Following is another example demonstrating the lastIndexOf() method in JavaScript:
<!DOCTYPE html>
<html>
<body>
<p id="abc"></p>
<script>
const myarray = ["Tokyo", "Bangkok", "Tokyo", "Dubai", "Berlin", "Tokyo", "Frankfurt"];
let lio = myarray.lastIndexOf("Tokyo", 3);
document.getElementById("abc").innerHTML = lio;
</script>
</body>
</html>If I remove 3 (the value of the start parameter), then the output should be 5. Because the last Tokyo is at index number 5. But since I specified 3, that's where to start the search. Therefore, the last Tokyo before index number 3 is available at index number 2.
« Previous Tutorial Next Tutorial »