# JavaScript Exercises: Get index of an given element in a Singly Linked list

## JavaScript Singly Linked List: Exercise-17 with Solution

Write a JavaScript program to get the index of an element in a Singly Linked list.

Sample Solution:

JavaScript Code:

``````class Node {
constructor(data) {
this.data = data;
this.next = null;
}
}
}
if(node==null){
return;
}
while (node.next) {
node = node.next;
}
node.next = newNode;
}

index_of(el) {
let index = 0;
while (node) {
if (node.data === el) {
return index;
}
node = node.next;
index++;
}
return -1;
}
displayList(){
var str = ""
while (node) {
str += node.data + "->";
node = node.next;
}
str += "NULL"
console.log(str);
}
}
numList.displayList();
result = numList.index_of(12);
console.log("Index of 12 in the said link list: "+result);
result = numList.index_of(13);
console.log("Index of 13 in the said link list: "+result);
result = numList.index_of(14);
console.log("Index of 14 in the said link list: "+result);
result = numList.index_of(16);
console.log("Index of 16 in the said link list: "+result);
```
```

Sample Output:

```Singly Linked list:
12->13->14->15->14->16->NULL
Index of 12 in the said link list: 0
Index of 13 in the said link list: 1
Index of 14 in the said link list: 2
Index of 16 in the said link list: 5
```

Flowchart:

Live Demo:

See the Pen javascript-singly-linked-list-exercise-17 by w3resource (@w3resource) on CodePen.

Improve this sample solution and post your code through Disqus

Singly Linked List Previous: Convert a Singly Linked list into a string.
Singly Linked List Next: Check if an element is present in the Singly Linked list.

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## JavaScript: Tips of the Day

Initialize an Array with Values

We can use the Array constructor with the fill method to create an array and fill it with items. For instance, we can write:

```Array(20).fill(10)
```

to create an array with 20 empty slots, then fill the slots with 10.

Ref: https://bit.ly/3mp5NgH