JavaScript: Generates a string id (specified length) of random characters

Last update on May 30 2022 09:59:07 (UTC/GMT +8 hours)

JavaScript Function: Exercise-20 with Solution

Write a JavaScript function that generates a string id (specified length) of random characters.

Sample character list : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"

Sample Solution: -

HTML Code:

<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>Generates a string id (specified length) of random characters</title>
</head>
<body>
  
</body>
</html>

JavaScript Code:

function makeid(l)
{
var text = "";
var char_list = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
for(var i=0; i < l; i++ )
{  
text += char_list.charAt(Math.floor(Math.random() * char_list.length));
}
return text;
}
console.log(makeid(8));

Sample Output:

4SGqCfrz

Flowchart:

Live Demo:

See the Pen JavaScript - Generates a string id (specified length) of random characters-function-ex- 20 by w3resource (@w3resource) on CodePen.

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Next: Write a JavaScript function to get all possible subset with a fixed length (for example 2) combinations in an array.

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JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = [];
arr[0] = "Jani";
arr[1] = "Hege";
arr[2] = "Stale";
arr[3] = "Kai Jim";
arr[4] = "Borge";

console.log(arr.join());
arr.splice(2, 0, "Lene");
console.log(arr.join());

Ref: https://bit.ly/2BXbp04