Pad a string using random numbers to a fixed length using javascript

Question

I am looking to pad a string with random numbers to meet a certain length (i.e. 10 characters). For example:

HAM --> HAM3481259 or TURKEY --> TURKEY6324

I've tried some JavaScript functions but I either had too many or no numbers at all. Any suggestions would be greatly appreciated.

What are you having trouble with here? What part of this are you stuck on? What have you tried? What do you mean by "tried some JavaScript functions"? — gen_Eric
– gen_Eric, Commented Apr 10, 2017 at 21:38
If you need to figure out how many characters you need to pad, you can do 10 - str.length (or 10 - (str.length % 10) after checking if str.length % 10 > 0). — gen_Eric
– gen_Eric, Commented Apr 10, 2017 at 21:39

Nina Scholz · Accepted Answer · 2017-04-10 21:35:39Z

3

You could check the length and add a random digit, if smaller than the wanted length.

function padRandom(string, length) {
    while (string.length < length) {
        string += Math.floor(Math.random() * 10);
    }
    return string;
}

console.log(padRandom('HAM', 10));
console.log(padRandom('TURKEY', 10));

answered Apr 10, 2017 at 21:35

Nina Scholz

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4 Comments

M Haase Over a year ago

What if I wanted to throw in padding with white space to this function? I know it can be done but I am inexperienced with functions but am trying to learn based on examples!

Nina Scholz Over a year ago

then add the space instead of Math.floor(Math.random() * 10)

M Haase Over a year ago

how about making it leading so that all of the existing characters are to the right?

Nina Scholz Over a year ago

i suggest to ask a new question. does any of the here given answers answers your question? you could have here a look, too: stackoverflow.com/help/someone-answers

Community · Accepted Answer · 2017-05-23 11:47:25Z

0

Slightly faster version of Nina's answer:

function padRandom(string, length) {
    random_number_length = length - string.length;

    if (random_number_length > 0) {
        string += randomFixedInteger(random_number_length);
    }

    return string
}

function randomFixedInteger(length) {
    return Math.floor(Math.pow(10, length-1) + Math.random() * (Math.pow(10, length) - Math.pow(10, length-1) - 1));
}

console.log(padRandom('HAM', 10));
console.log(padRandom('TURKEY', 10));

edited May 23, 2017 at 11:47

CommunityBot

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answered Apr 10, 2017 at 22:47

fedeisas

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