Posts by Sergio • 133,294 points
2,786 posts
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viewsA: Is declaring variable receiving element of a vector within a for a good practice or is it unnecessary?
There are slight performance implications when declaring variables, but in most cases easy to read code is preferable. Take a look to this test, and notice how the last example is slower. With ES6…
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viewsA: How to reference the first loop from the second in a chain of loops?
Yes, you can use continue 2;, you can see that in documentation on control structures. continue accepts an optional numerical argument that tells you how many nested loop levels to skip. Default…
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answers2363
viewsA: Enable 'Access-Control-Allow-Origin' in jQuery [xml]
The Access-Control-Allow-Origin can only be activated on the server. The purpose of this rule is that the browser cannot access content that the server does not want accessed when the request domain…
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answer644
viewsA: Object.<Anonymous> (Express + Middleware)
express has separated some of its plugins/middlewares into separate components. So, you can use only: app.use(express.cookieParser()); now you have to import one by one and use: const cookieParser =…
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viewsA: The logic behind how PHP interprets string and number concatenation?
The problem is that when PHP converts strings to number it gives 0 if the string has no digits at the beginning. That is: echo intval('4string'); // 4 echo intval('string4'); // 0 echo…
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viewsA: Trying to fill an array with days from now until thirty days from now
You can use the setDate() to change a date object and then know the day with getDate(). var dias = 30; var hoje = new Date(); var primeiroDia = hoje.getDate(); var array = []; for (var i = 0; i <…
javascriptanswered Sergio 133,294 -
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answers100
viewsA: How to resolve page redirection in form?
You’re using the wrong selector, that code actually never runs because the button #submit has no event submit, only the <form> is what it is. Or you use .click on the button, or you use…
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answers381
viewsA: Fill value in combobox when you click checkbox
You can do this only with Javascript and using the object property directly. function IEcli() { var cbocontribuinte = document.getElementById('tp_contribuinte'); var iecli =…
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answer203
viewsA: How to make a jquery global variable?
At times var id uses window.id, or a more secure name not to be overwritten as window.randomId. This type of programming is not recommended because it generates code difficult to maintain, read and…
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answers153
viewsA: Next 0-Z Sequence Code with Javascript
If you know the String that you have of characters you can use a loop to make these changes/increments. Using flags to coltrolar if you should increment. Suggestion: var Next = (function(seq) { var…
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viewsA: What is Encryption ($) for before a Function in Javascript?
This is typical of jQuery. The $ is the jQuery library alias and this function is similar to window.onload, ie: run when document has loaded. Anyway the $ has no special meaning in Javascript. It is…
javascriptanswered Sergio 133,294 -
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answer91
viewsA: How to remove some characters from a var javascript?
You can create a regex to find the first number: var tempo = "Rolling in 8.31..."; var match = tempo.match(/[^\d](\d+)/); var nr = match && match[1]; console.log(nr); // 8 Or cut the string…
javascriptanswered Sergio 133,294 -
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answer2316
viewsA: CRUD Mysql with Nodejs: how to use Pool correctly?
In your model.js flames once mysql.createPool. This is correct and only happens once, when the program loads, then every call to the database uses getConnection and release. To use Mysql return you…
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answer1477
viewsA: How do I rotate an image with jquery?
You can use the transform: rotate(7deg); for this and do transition: transform 2s; for smooth rotation. var btn = document.querySelector('button'); var img = document.querySelector('img');…
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answers289
viewsA: Express How to make a div appear only if the user is logged in?
The passport adds a property .user at the request and usually has a function like this: function gateKeeper(req, res, next){ let environment = express().get('env'); if (req.user) next(); else…
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answer3849
viewsA: Run a shell script with Nodejs
If you want to run a script .js best is to create functions in these scripts and do require or import these scripts so you can run these functions when needed. If the scripts are not Javascript you…
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answer23
viewsA: Difficulty in passing parameters and arguments in callback
The this is internal to the first function and passes as argument to the second, then the signature of the second function should be function input_nome_Ajax(value){ and then you can use it like…
javascriptanswered Sergio 133,294 -
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answers124
viewsA: Callback running when loading the page
If you want to save a reference to the element being iterated you can use .bind() that will create a function, passing as first argument the element. But you really don’t need to pass up your job…
javascriptanswered Sergio 133,294 -
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answer64
viewsA: Function generator returns Undefined
The yield is like a return in generating functions, that is when the function reads the yield gives the expression that is after it (the strings you have) and pauses the execution of the function.…
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answers1154
viewsA: How to count the elements of a jquery li
You can mount an array with the value of how many elements each li has. It would be something like this: var contador = $('ul li').get().reduce(function(obj, li) { obj[li.id] = li.children.length;…
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answer998
viewsA: How to show result via ajax and jquery without refresh happening on the page
If you do not want to reload the page by clicking the button changes the type="submit" for type="button" then changes onclick="updatePost" for id="updatePost", so your jQuery selector will already…
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viewsA: Replicate DIV, alter content?
Assuming the property that you set the answer to the api in artigos I suggest you have a loop to iterate this array that the API gives and within that loop have a if to duplicate the content.…
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viewsA: Regular expression for accepting numbers and letters, regardless of sequence
I think it will be difficult a regex that covers all cases. It would be easier to count the characters and numbers and check at the end. Suggestion: var testes = ["12abcdef", "abcdef12", "1a2b3c4d",…
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answers431
viewsA: Get all the ID of the elected in jQuery
You can use the .toggleClass(classe, condição) passing you the ID check to know whether to add or remove the class. Example: var idEspecial = 'menu1'; $('div[id^=menu').each(function() {…
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viewsA: How to Drag and Drop button in a textarea?
Here’s a hint with native drag & drop (HTML5). The idea is to associate the string you want in dragstart and then extract in the drop to concatenate with the value already existing in the…
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answer595
viewsA: What is the hreflang attribute for?
The idea of this attribute is to indicate which language of the anchor link the attribute is in. This is useful in terms of SEO for the search engine to better organize content. This attribute is…
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viewsA: Get row item except for one column
You can classify that column and delete it with if (e.target.classList.contains('excluir')) return; Example: $("tr").on('click', function(e) { if (e.target.classList.contains('excluir')) return; var…
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viewsA: How to return these values outside the Array?
It seems to me that you want to map the values, and for that there is .map() which creates a new array with the return of each loop iteration that the .map() calf. You can use it like this: var…
javascriptanswered Sergio 133,294 -
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answer217
viewsA: setCustomValidity does not work with Ajax
To trigger the error you must perform form Ubmit. It is not possible to trigger the validation only in one element. You can know if it’s valid, like you asked with the .checkValidity() but this does…
javascript-eventsanswered Sergio 133,294 -
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answers147
viewsA: I cannot use Boundary( b) to validate a word starting with "@"
The problem is that @ is not considered a valid character for word. That is to say: \b refers to the beginning of a word but the characters valid for \w sane [a-zA-Z0-9_], and @ is not there.…
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answer176
viewsA: jQuery read json and show sublevels only if they exist
You can make a recursive function that checks if one of the keys is an object, for example with if (typeof prop === 'object'). A suggestion would be so: var content = { "primeiroNivel0": { "title":…
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viewsA: Javascript function when clicking on any class="foo"
You can do as Rafael suggested or add a global headphone, which acts as a delegator for elements not yet created when the page uploaded. It would look like this:…
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viewsA: Should I use a variable that takes an HTML element as global or local?
Variables declared within functions are deleted from memory after the function runs. So in terms of memory management the variable within the function is best. Another good point to bear in mind is…
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viewsA: Take two "arrays" in one line?
With ES6 you can do it in one line like this: [...document.getElementsByClassName("teste")].forEach(el => el.removeAttribute("disabled")); But with "old" Javascript it has to be with a loop: var…
javascriptanswered Sergio 133,294 -
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answers2243
viewsA: Doubt random string with Javascript
A solution to N names, without needing to change more in the code. Create an array with the names you want to use and then use Math.ceil(Math.random() * (nomes.length - 1)) as input of the item to…
javascriptanswered Sergio 133,294 -
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answers31
viewsA: jQuery doubt all elements are affected by the function
The rule is: collect all but what was clicked, this gets toggle. I also suggest controlling the arrows with CSS, so you only need to change the class active and the rest "happens for you". Example:…
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viewsA: Help to filter a JSON with jQuery?
What you need is: var filtrados = json.aPesquisa.map(obj => { return obj.trecho.map(trecho => { return trecho.voo.filter(voo => { return horasParaMinutos(voo.hrDuracao) <= duracao });…
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viewsA: Get TD value by clicking on table
To know the value of the first column of each row you can use something like this: $("tbody tr").on('click', function() { var hora = this.firstElementChild.textContent; console.log(hora); }); Then…
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answers7978
viewsA: Change`id` of <Form> javascript or jquery element
To change the ID you can change the property of the DOM object or the attribute of the HTML element. These are different things, I explained more about this here in this other answer. Change…
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answers994
viewsA: How to read Console strings?
The browser does not allow Javascript code to read the console contents. Probably for security reasons. Short answer, but I see no way around, at least in the browser.
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viewsA: How to insert Javascript with Javascript?
The tag <javascript> is not search, would be <script>. But when you insert </script> with Javascript inside HTML this doesn’t work. It doesn’t work because some browsers see the…
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answer34
viewsA: app.set('x-powered-by', false) does not work on expressjs
I use it like this with Elmet: app.use( helmet({ hidePoweredBy: { setTo: 'Renewable energies, love and good music' } }) ); And if you want you can pass an empty string on setTo.…
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answer60
viewsA: How to access a JSON value and enter data-id?
You just need to iterate obj.data and generate a <a> with the array’s input. Example: var obj = { draw: 1, recordsTotal: 16, recordsFiltered: 16, data: [ ["1", "FooBar", "00.000.000/0000-00",…
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viewsA: Validation of elements of a javascript array
You were making a comparison .value > 0 and that’s a boolean, so when you do the if(... == 0) This will never come true because the IsNumericString is boolean and not length/numeric. function…
javascriptanswered Sergio 133,294 -
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viewsA: Take the last position of a split()
Suggestion: var partes = nome.split(' '); var formatado = [partes.pop().toUpperCase(), partes.join(' ')].join(', '); The idea is: separate by spaces (as you already had) create an array with 2…
javascriptanswered Sergio 133,294 -
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answer84
viewsA: Script does not work on IE but works on other browsers
In some browsers you can access elements directly with the id, that is, there is an element with id "central" it can be accessed as a global variable window.central. That’s a very bad idea (I’ve…
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viewsA: Error in the formation of the website title
You’re doing the concatenation wrong, that close tag php should appear later at the end of the concatenation: <?php echo $nomeproduto.' - Vendas'; ?>…
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answer23
viewsA: Apply a class to the Selected tag
You can use li[selected] selector, but I suggest doing this with CSS classes and then using li.selected on the selector. But as I mentioned with li[selected] works, ie: .horizontal-menu li:hover,…
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viewsA: addClass inside this
If .seta is descended from this you can do it like this: $(this).find('.seta').addClass('seta_ativa'); // ou alternativamente: $('.seta', this).addClass('seta_ativa'); Example:…
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answer1186
viewsA: How do I reset the third decimal place in php?
You have to use the second argument of that function round which is exactly the number of decimal places, the accuracy. Example: echo round(3.425); // 3 echo round(3.425 , 1); // 3.4 echo…