Develop Reference

Generate random 6 characters based on input

Generate random 6 characters based on input. Like I want to turn 1028797107357892628 into j4w8p. Or 102879708974181177 into lg36k but I want it to be consistant. Like whenever I feed 1028797107357892628 in, it should always spit out j4w8p. Is this possible? (Without a database if possible.) I know how to generate random 6 characters but I dont know how to connect it with an input tbh. I would appreciate any help, thanks.
let rid = (Math.random() + 1).toString(36).substring(7);

You can create a custom hashing function a simple function to your code would be
const seed = "1028797089741811773";
function customHash(str, outLen){
//The 4 in the next regex needs to be the length of the seed divided by the desired hash lenght
const regx = new RegExp(`.{1,${Math.floor(str.length / outLen)}}`, 'g')
const splitted = str.match(regx);
let out = "";
for(const c of splitted){
let ASCII = c % 126;
if( ASCII < 33) ASCII = 33
out += String.fromCharCode(ASCII)
}
return out.slice(0, outLen)
}
const output = customHash(seed, 6)
console.log(output)

It is called hashing, hashing is not random. In your example to get rid:
let rid = (Math.random() + 1).toString(36).substring(7);
Because it is random, it's impossible to be able to produce "consistant result" as you expect.
You need algorithm to produce a "random" consistant result.

Thanks everyone, solved my issue.
Code:
let seed = Number(1028797089741811773)
let rid = seed.toString(36).substring(0,6)
console.log(rid)
Or:
let seed = Number(1028797089741811773)
let rid = seed.toString(36).substring(6)
console.log(rid)

Adding space to fill array length

I am working with a javascript program that needs to be formatted a certain way. Basically, I need to have each section of information from an array be a set length, for example 12 characters long, and no more than that.
The problem I am running into comes when a value in the array is NOT 12 characters long. If I have a value that is less than the 12 characters the remaining character allotment needs to be filled with blank spaces.
The length of each section of information varies in size and is not always 12. How can I add X number of blank spaces, should the length not meet the maximum requirement, for each section?
This is where I am at with adding space:
str = str + new Array(str.length).join(' ');
I am pretty sure what I have above is wrong but I believe I am on the right track with the .join function. Any ideas?
EDIT: I was asked to show a wanted outcome. It is a bit complicated because this javascript is being run out of a web report tool and not out of something like Visual Studio so its not traditional JS.
The outcome expected should look something like:
Sample Image
So as shown above the data is in one line, cutting off longer strings of information or filling in blank spaces if its too short for the "column" to keep that nice even look.

try this code and leverage the wonders of the map function:
let say your array is:
var myArr = ["123456789012", "12345678901", "123"];
now just apply this function
myArr.map(function(item){ //evalueate each item inside the array
var strLength = item.length; //apply this function to each item
if (strLength < 12){
return item + ' '.repeat(12-item.length) //add the extra spaces as needed
} else {
return item; // return the item because it's length is 12 or +
}
})
What you are looking for is the ' '.repeat(x) - where x is the times you want to repeat the string you have set, it could be '*'.repeat(2) and you would get '**', if you want to understand more about it look at the docs

depending on which version of javascript, this might work:
if (str.length < 12) str += ' '.repeat(12 - str.length);

Not exactly sure how you're setup -- but something like the following will accept an array and return another array with all its values being 12 characters in length.
var array = ['Test', 'Testing', 'Tested', 'This is not a Test'];
var adjustedArray = correctLength(array, 12);
function correctLength(array, length) {
array.map(function(v, i) {
if (array[i].length < length) {
array[i] += Array((length+1) - array[i].length).join('_');
}
// might not need this if values are already no greater than 12
array[i] = array[i].substring(0, length);
});
return array;
}
console.log(adjustedArray);

I want to obtain a certain part of text from a large webpage using Javascript, how do I?

There is a certain webpage which randomly generates a number, for example "Frequency : 21". I am trying to create a script which takes the number, 21, and compares it to another variable, then to an if else function. Basically, I've completed most of it, but I can't obtain the number 21. And since it is random, I can't put in a fixed value.
Can anyone help me out?
My code goes like:
setTimeout(MyFunction,5000)
function MyFunction(level,legmin) {
var level = x
var legmin = 49
if (level <= legmin) {
location.reload(true)
}
else {
alert("Met requirements.")
}
where the address of the text I want is:
html>body>div#container>div#contentContainer>div#content>
div#scroll>div#scrollContent>div>div>div#pkmnappear>form>p (x in the code above).

A quick-n-dirty solution without regex.
var lookFor = "Frequency : ";
var text = document.querySelector("#pkmnappear>form>p").textContent;
var level = text.substr(text.indexOf(lookFor) + lookFor.length).split(" ")[0];
This assumes the number will be followed by a space

I would like to get the value of a given token with in a string

I am currently working on a project that will allow me to bring in a string that would have a designated token that I will grab, get the designated value and remove the token and push to an array. I have the following condition which I am using split in JavaScript but it is not splitting on the designated ending token.
This is the beginning string
"~~/Document Heading 1~~<div>This is a test <b>JUDO</b> TKD</div>~~end~~<div class="/Document Heading 1">This is a test <b>JUDO</b> TKD</div>"
Current Code Block
var segmentedStyles = [];
var contentToInsert = selectedContent.toString();
var indexValue = selectedContent.toString().search("~~");
if (indexValue <= 0) {
var insertionStyle = contentToInsert.split("~~");
segmentedStyles.push(insertionStyle);
}
The designated token is enclosed by a "~~ .... ~~". In this code Block it is going through the condition but the string it is not splitting correctly. I am currently getting the Following string pushed to my array.
This is my current result
[,/Document Heading 1<div>This is a test <b>JUDO</b> TKD</div>end,
<div class="/Document Heading 1">This is a test <b>JUDO</b> TKD</div>]
My Goal
I would like to split a string that is coming in if a token is present. For example I would like to split a string starting from ~~.....~~ through ~~end~~. The array should hold two values like the following
segmentedStyles = [<div>This is a test <b>JUDO</b> TKD</div>],[<div class="/Document Heading 1">This is a test <b>JUDO</b> TKD</div>]

You could use a regular expression for matching the parts.
var string = '~~/Document Heading 1~~<div>This is a test <b>JUDO</b> TKD</div>~~end~~<div class="/Document Heading 1">This is a test <b>JUDO</b> TKD</div>',
array = string.split('~~').filter(function (_, i) {
return i && !(i % 2); // just get element 2 and 4 or all other even indices
});
console.log(array);

Assuming the string always starts with ~~/ you could use the following regex to get the array you want
~~([^\/].*)~~end~~(.*)
https://regex101.com/r/hJ0vM4/1

I honestly didn't quite understand what you're trying to accomplish haha, but I sort of understood what you're trying to do :)
First, just trying to make it clear some stuff. If you split() your string using /~~/ as the Regular Expression for splitting you'll get all the bits surrounded by "~~" in an array, like you did.
Second, if you change the tokens to ~~START~~ and ~~END~~ (tokens that never change) you can accomplish what you want by simply doing string.split(/~~(START|END)~~/) - Much shorter and quicker ;)
Third is the string always in the format ~~<something>~~THE STUFF YOU WANT~~end~~MORE STUFF YOU WANT? If it is, I'd suggest doing this:
function splitTheTokens(str) {
var result = [];
var parts = str.split(/~~end~~/);
for (var i = 0; i < parts.length; i++) {
if (!parts[i]) { continue; } // Skips blanks
if (parts[i].indexOf("~~") == 0) {
// In case you want to do something with the name thing:
var thisPartName = parts[i].substring(2, parts[i].indexOf("~~", 2));
// What (I think) you actually want
var thisPartValue = parts[i].substring(thisPartName.length + 4);
result.push(thisPartValue);
}
else {
result.push(parts[i]);
}
}
return result;
}
Hope this helps :D

Eval alternative

This code works as a calculator, but the scratch pad at codeacademy tells me that eval is evil. Is there another way to do the same thing without using eval?
var calculate = prompt("Enter problem");
alert(eval(calculate));

eval evaluates the string input as JavaScript and coincidentally JavaScript supports calculations and understands 1+1, which makes it suitable as a calculator.
If you don't want to use eval, which is good, you have to parse that string yourself and, finally, do the computation yourself (not exactly yourself though). Have a look at this math processor, which does what you want.
Basically what you do is:
Read the input string char by char (with this kind of problem it's still possible)
Building a tree of actions you want to do
At the end of the string, you evaluate the tree and do some calculations
For example you have "1+2/3", this could evaluate to the following data structure:
"+"
/ \
"1" "/"
/ \
"2" "3"
You could then traverse that structure from top to bottom and do the computations.
At first you've got the "+", which has a 1 on the left side and some expression on the right side,
so you have to evaluate that expression first. So you go to the "/" node, which has two numeric children. Knowing that, you can now compute 2/3 and replace the whole "/" node with the result of that. Now you can go up again and compute the result of the "+" node: 1 + 0.66. Now you replace that node with the result and all you've got left is the result of the expression.
Some pseudo code on how this might look in your code:
calculation(operator, leftValue, rightValue):
switch operator {
case '+': return leftValue + rightValue
case '-': return 42
}
action(node):
node.value = calculation(node.operator, action(node.left) action(node.right))
As you might have noticed, the tree is designed in such a way that it honors operator precedence. The / has a lower level than the +, which means it get's evaluated first.
However you do this in detail, that's basically the way to go.

You can use the expression parser that is included in the math.js library:
http://mathjs.org
Example usage:
mathjs.evaluate('1.2 / (2.3 + 0.7)'); // 0.4
mathjs.evaluate('5.08 cm in inch'); // 2 inch
mathjs.evaluate('sin(45 deg) ^ 2'); // 0.5
mathjs.evaluate('9 / 3 + 2i'); // 3 + 2i
mathjs.evaluate('det([-1, 2; 3, 1])'); // -7

You can use eval safely for a simple arithmetic calculator by filtering the input- if you only accept digits, decimal points and operators (+,-,*,/) you won't get in much trouble. If you want advanced Math functions, you are better off with the parser suggestions.
function calculate(){
"use strict";
var s= prompt('Enter problem');
if(/[^0-9()*+\/ .-]+/.test(s)) throw Error('bad input...');
try{
var ans= eval(s);
}
catch(er){
alert(er.message);
}
alert(ans);
}
calculate()

I write some functions when I had a problem like this. Maybe this can help:
data = [
{id:1,val1:"test",val2:"test2",val2:"test3"},
{id:2,val1:"test",val2:"test2",val2:"test3"},
{id:3,val1:"test",val2:"test2",val2:"test3"}
];
datakey = Object.keys(data[0]);
// here's a fix for e['datakey[f]'] >> e[x]
vix = function(e,f){
a = "string";
e[a] = datakey[f];
x = e.string;
end = e[x];
delete e.string;
return end;
};
// here's a fix to define that variable
vox = function(e,f,string){
a = "string";
e[a] = datakey[f];
x = e.string;
end = e[x] = string;
delete e.string;
};
row = 2 // 3th row ==> {id:3,val1:"test",val2:"test2",val2:"test3"}
column = 1 //datakey 2 ==> val1
vox(data[row],column,"new value");
alert(data[2].val1); //the value that we have changed