Javascript get all numbers

Javascript get all number by express

You can get all the numbers using ‘*’ This array can be used to iterate over params. e.g req.params[0] for will return and after splitting using split function it will be . In this case, however, the number of parameters the route can handle is limited to 3 (or however many url parameters I hard code).

How to capture indefinite number of parameters in Express Route?

Say I have an express route that takes numbers, adds them all up and returns the total.

Normally I would do something like this

app.get('/add/:num1/:num2/:num3', (req, res) => < // access and parseInt these values from req.params // do operations // return total >) 

In this case, however, the number of parameters the route can handle is limited to 3 (or however many url parameters I hard code). What if I wanted to handle an indefinite or unknown number of parameters? In this case, numbers?

Ultimately I want the route to be able to handle 2, 3, 5, 10, or 20 numbers if that’s what the user sends.

Express route supports * wildcard . You can get all the numbers using ‘*’

This array can be used to iterate over params.

e.g req.params[0] for GET /add/1/2/4/6 will return 1/2/4/6 and after splitting using split function it will be [1,2,4,6] . And finally add operation can be done on elements of array.

How to call only a certain number of arrays in an external api with express.js

I am currently learning about external API’s using axios, express, and node. This is the code I am using to call the API:

app.get("/externalapi", (req, res) => < ; let apiURL = 'https://makeup-api.herokuapp.com/api/v1/products.json'; axios.get(apiURL) .then(response =>< res.status(200).json(response.data); >) .catch((err) => < res.status(500).json(< message: err >); >); >); 

This code would successfully return ALL the data in that API when I use a GET request from Postman. However, I would only like to call the first 10 arrays of that API. an example data of the API is:

I know you have to use a for loop to call only a certain number of arrays. However, I have almost no idea how to go about that and I would love to learn how to do it. May I please ask of some assistance. I know it’s a simple question but I am a beginner trying to learn how to call and manipulate data from external API’s

The .slice() method should help

res.status(200).json(responde.data.slice(0, 10)); 

Node.js — How to access the GET parameters after «?» in Express?, params[‘id’] . req.query and req.body will be populated with all params, regardless of whether or not they are in the route.

Getting a json back from express.js using a jQuery get method does not work

I am trying to pass a value as JSON from my back end to the front end of my application. I am currently running express.js and the connection for all post methods is PERFECT.

Upon a button click in the FRONT-END in my application I want to get back an invoice number from my server.

On the front end my code looks like this with jQuery:

$.get("/invoiceNumber", function(data) < console.log(data.number); >); 

On the back end it looks like this:

app.get("/invoiceNumber", function(req, res) < res.json(< number: 4 >); >); 

Currently I am passing 4 just as a test.

The Error I am getting is:

GET http://127.0.0.1:3000/invoiceNumber 404 (Not Found) 

If I try to go directly to:

it looks that this question is duplicated How to allow CORS?

your App.js

var express = require('express') var cors = require('cors') var app = express() app.use(cors()) app.get('/products/:id', function (req, res, next) < res.json() >) app.listen(80, function () < console.log('CORS-enabled web server listening on port 80') >) 

you can find additional information here https://expressjs.com/en/resources/middleware/cors.html#enable-cors-for-a-single-route

Looks to me like you need to refrence where you back end is running from:

$.get("/invoiceNumber", function(data) < console.log(data.number); >); 

if your express app is running on port 3000, change your front end to the following:

$.get("localhost:3000/invoiceNumber", function(data) < console.log(data.number); >); 

Regex using javascript to return just numbers, I guess you want to get number(s) from the string. In which case, you can use the following: // Returns an array of numbers located in the

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How to Extract Numbers From a String in JavaScript

Including decimals, negatives, and numbers with commas.

While working on certain tasks with JavaScript, such as web scraping, we might need to extract specific data from a string, such as uppercase words or numbers. In this post, I am going to address numbers.

• decimal — examples: average, price, score.
• negative — examples: temperature, mathematical calculations.
• comma-separated — example: large amounts such as appear in telephone numbers or bank statements.

Or a combination of any of these.

For example, a simple short text such as:

The World Population at the start of 2023 is 8,009,975,957. It crossed 8 billion mark in 2022. 

or in number form (without string/commas):

To see it working interactively, provide a text to this Extract Numbers utility app, and get a list of extracted numbers.

To get all the possible numbers out of the string requires a regex. And I’ve found one that addresses most of the above cases, plus their combinations.

In case you are looking for a JavaScript library, it’s available as extract-numbers on NPM. It has no dependency.

The Regex And The Code

Regex

Code

const extractNumbers = (text, options) =>  let numbers; if (!text || typeof text !== 'string')  return []; > numbers = text.match(/(-\d+|\d+)(,\d+)*(\.\d+)*/g); return numbers; >; 

Code to Optionally Convert the Resultant Strings to Numbers

Change the method call to extractNumbers(str, ); , and replace the function code with:

const extractNumbers = (text, options) =>  let numbers; options = options || <>; if (!text || typeof text !== 'string')  return []; > numbers = text.match(/(-\d+|\d+)(,\d+)*(\.\d+)*/g); if (options.string === false)  numbers = numbers.map(n => Number(n.replace(/,/g, ''))); > return numbers; >; 

See also

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How to Get Numbers from a String in JavaScript

There are many ways you can extract or get numbers of a string in JavaScript. One of the simplest ways of extracting numbers from a given string in JavaScript is using Regex or Regular Expressions.

Let us assume I have a string value, a name, suffixed with some random numbers.

I want to extract the number 4874 from the above string and there are two simple methods to this.

1) Using RegEx \d Metacharacter

The metacharacter \d search for digits , which are also numbers. The match() method uses regular expressions to retrieve it results. When used the match() with \d , it returns the number 4874 .

However, the above method will return the first occurrence of the numbers. Therefore, if you have a string like arun_4874_541 , using the above method, will return only 4874 .

To get all the numbers 4874 and 541 , you’ll have to use g modifier, which means global (or perform a global search). Here’s how you should do this.

2) Using RegEx \D Metacharacter

Metacharacters are case sensitive and has unique meanings. In the first example above, I have used \d (lower case) and now I’ll use \D upper case.

<script> var tName = 'arun_4874'; alert(tName.replace(/\D/g, '')); // do a global search for non digit characters and replace is with ''. </html>

The metacharacter \D (with the g modifier) does a global search for non-digit characters, which returns arun_ . And, using the replace() method, I am replacing arun_ with a blank character (»). What remains is the number 4874 and this is our result.

We saw two different metacharacters in action with two different methods, to extract only numbers from a string (any string).

Extract Numbers from an Element’s id using JavaScript

Here’s another example, where I am extracting numbers from an element’s id and its contents (some text). I am using one of methods that I have described in the above examples.

<html> <head> <title>Extract Numbers from String using JavaScript</title> </head> <body> <p > Showing 129 items from our inventory, out of which 6 are sold. </p> <input type="button" value="Click it" onclick color:#000;">getNumberOnly()" /> </body> <script> function getNumberOnly() < var p = document.getElementById('prod21'); var n1 = p.id.match(/\d+/); // Get numbers from element's id. var n2 = p.innerHTML.match(/\d+/g); // Get numbers from element's content. alert(n1 + ' and ' + n2); > </script> </html>

Well, that’s it. Thanks for reading. ☺

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