it seems to think ttinput is a string when I console.log the variable it says "". All else seems to working I just can't figure out how to have ttinput as a number.
document.getElementById("enter").addEventListener("click", ttcalc)
var ttinput = document.getElementById("table").value;
var ttoutput;
function ttcalc(){
var display = "";
for(var i = 1; i <= 12; i++){
ttoutput = ttinput * i;
display += ttinput + "*" + i + "=" + ttoutput + "<br>"
console.log(ttoutput, ttinput, i);
}
document.getElementById("output").innerHTML = display;
}
this is my html
<form>
<h1>Enter what times table you wish to see</h1>
<input type="number" id="table"><br>
</form>
<button id="enter">Show Times Table</button>
</div>
The problem is that the value of
var ttinput = document.getElementById("table").value;
is read on page load (while the input field is empty). If you move that line of code inside your function it will read the value of the input field after the button is clicked.
If you want to be sure the value entered is a number you can use the parseInt() function and then check if the result is a number with the isNaN() function like this:
var ttinput = parseInt(document.getElementById("table").value);
and then use isNaN():
if( !isNaN(ttinput) ) {
// ttinput is a number
} else {
// ttinput is not a number
}
More here: parseInt and isNaN.
Check example below:
document.getElementById("enter").addEventListener("click", ttcalc)
function ttcalc() {
var ttinput = parseInt(document.getElementById("table").value);
var ttoutput;
var display = "";
if( !isNaN(ttinput) ) {
for(var i = 1; i <= 12; i++) {
ttoutput = ttinput * i;
display += ttinput + "*" + i + "=" + ttoutput + "<br>"
console.log(ttoutput, ttinput, i);
}
document.getElementById("output").innerHTML = display;
} else {
console.log("value is not a number");
}
}
<button id="enter">Enter</button>
<input type="text" id="table" value="">
<div id="output"></div>
Related
I am practicing creating a function that loops whatever number I put into the input into a times table. I used a for loop to achieve this but I ran into an issue. My for loop only runs one time and it only get my input * 10 for some reason. Can someone please help. Thank you.
function myFunction() {
var inputNumber = document.querySelector(".input-field").value;
inputNumber = parseInt(inputNumber);
if (isNaN(inputNumber) || inputNumber == "" || inputNumber == null) {
document.querySelector(".output h1").innerHTML = "Please enter a number!";
} else {
for (i = 1; i <= 10; i++) {
let product = inputNumber * i;
document.querySelector(".output").innerHTML = "<br>" + inputNumber + " * " + i + " = " + product + "<br>";
}
}
}
Looks like you update the HTML on every iteration. However, I think you want to expand the innerHTML to include all elements?
I would look into creating html elements in javascripts and adding them in html like this (draft, untested):
const element = document.createElement("div")
for (let i = 1; i < 10; i++) {
let product = inputNumer * i;
element.appendChild(document.createTextNode(`${inputNumer} ${product}`);
}
Please study this. It is using recommended event listener and a map
const arr = [...Array(11).keys()].slice(1); // numbers from 1 to 10
const h1 = document.querySelector("#output h1"),
result = document.getElementById("result"),
inputField = document.getElementById("inputField");
inputField.addEventListener("input", function() {
const inputNumber = +this.value;
console.log(inputNumber)
h1.classList.toggle("hide", inputNumber); // keep hide if ok number
result.innerHTML = inputNumber ? arr.map(i => `${inputNumber} * ${i} = ${inputNumber*i}`).join(`<br/>`) : "";
});
.hide {
display: none;
}
<input type="number" id="inputField" class=".input-field" />
<hr/>
<div id="output">
<h1 class="error hide">Please enter a number!</h1>
<div id="result">
</div>
</div>
What I want is, after the user enters the number of subjects, the system will show the number of input box according to the number of subjects entered, then when the user clicks on the button, it should show the sum. I tried many ways, but I failed to show the sum, anyone knows what is the mistake I made?
Below is my code:
function select() {
var x = parseInt(document.getElementById('1').value);
if (document.getElementById('1').value == "") {
alert("Please fill up number of subject");
} else if (isNaN(x) == true) {
alert("Please fill up number of subject with number");
} else {
var subject = parseInt(document.getElementById('1').value);
var sum = 0;
for (var num = 1; num <= subject; num++) {
document.write("Enter the mark for subject " + num + " : ");
var value = parseFloat(document.write("<input/><br>"));
sum += value;
}
var calc = document.write("<button>Next</button><br>");
calc.onclick = function() {
next()
};
function next() {
document.write("Total marks: " + sum + "%");
}
}
}
<html>
<body>
Enter the number of subject: <input type="text" onkeypress="return/[0-9]/i.test(event.key)" id="1" value=""><br>
<button onclick="select()">Check</button><br>
</body>
</html>
That's how I have rewritten a big part of your code. I have place inline comments to explain what I do.
function select() {
var x = parseInt(document.getElementById('1').value, 10);
// Getting the div that wraps the initial form.
var formWrapper = document.querySelector('.formWrapper');
// Getting the div, that is going to display the new fields and the results.
var results = document.querySelector('.results');
// I have switch your statement from x == '' to '' === x as it
// consists a good practice
if ( '' === x ) {
alert("Please fill up number of subject");
// I have remove the isNaN(x) == true, because the isNan will
// be either true or false.
} else if ( isNaN(x) ) {
alert("Please fill up number of subject with number");
} else {
// Using parseInt(x, 10) to set the base.
var subject = parseInt(x, 10);
// In this array, I store the auto-generated fields.
var fieldsList = [];
// Removing the first div from the DOM
formWrapper.parentElement.removeChild(formWrapper);
for ( var num = 1; num <= subject; num++ ) {
// I am creating a new field
var newField = document.createElement('input');
// I push the field into the array I made for the fields.
fieldsList.push(newField);
// I append the field in the HTML
results.appendChild(newField);
// I create a <br> tag
var br = document.createElement('br');
// And I append the tag in the DOM
results.appendChild(br);
}
// I create the button that is going to handle the Next functionality
var nextButton = document.createElement('button');
// I set the button text
nextButton.innerText = 'Next';
// I add an Event Listener for the click event.
nextButton.addEventListener(
'click',
function() {
// I reset the sum to 0
var sum = 0;
// I itterate the fields auto-generated and saved in the array
fieldsList.forEach(
function(field) {
// I get the value
sum += parseInt(field.value, 10);
}
);
// I create the field that is going to display the output
let resultText = document.createElement('div');
// I set the text based on the sum
resultText.innerText = "Total marks: " + sum + "%";
// I append the text message to the DOM
results.appendChild(resultText);
}
);
// I append the button to the DOM
results.appendChild(nextButton);
}
}
<html>
<body>
<div class="formWrapper">
Enter the number of subject: <input type="text" onkeypress="return/[0-9]/i.test(event.key)" id="1" value=""><br>
<button onclick="select()">Check</button><br>
</div>
<div class="results"></div>
</body>
</html>
Is there a function that splits the the given string into 2 evenly and place half of each to different textboxes?
I have tried var.split and var.slice
<script>
function display()
{
var myStr = document.getElementbyId("reqnum").value;
var strArray = myStr.split(" ");
// Display array values on page
for(var i = 0; i < strArray.length; i++){
document.write("<p>" + strArray[i] + "</p>");
}
}
the expected should split the no. evenly and would display an error if the numbers are odd.
You can check the length of your input string. If it is odd then display an error.
<input type="text" id="reqnum" >
<input type="button" value="Display" onclick="display()">
<script>
function display()
{
var myStr = document.getElementById("reqnum").value;
if( !myStr || myStr.length % 2 == 1){
document.write("<p>Invalid input</p>");
}else{
var a = parseInt(myStr.substring(0, myStr.length/2));
var b = parseInt(myStr.substring(myStr.length/2, myStr.length));
document.write("<p>" + a + "</p>");
document.write("<p>" + b + "</p>");
document.write("<p> Result after multiplication : " + (a*b) + "</p>");
}
}
</script>
you can convert the numbers to string and then you can do the following.
var num = "1234567890"
var num1
var num2
if (num.length % 2 == 0) {
num1 = num.slice(0, (num.length / 2))
num2 = num.slice((num.length / 2))
} else {
console.log("Number contains odd number of digits")
}
console.log("Num1 " + num1 + " and Num2 " + num2)
use the Slice method, documentation is here.
For your slicing in half:
let half1, half2;
if( myStr.length % 2 == 0 ){
half1 = myStr.slice(0, (myStr.length / 2));
half2 = myStr.slice( (myStr.length / 2), myStr.length );
} else {
// error code
}
function splitToEqual(num){
num = num.toString()
return [num.substring(0, num.length / 2), num.substring(num.length / 2, num.length)]
}
console.log(splitToEqual(1234567890))
Have you tried using slice and length String methods?
Ie.
const string = '1234567890';
const length = string.length;
const res1 = string.slice(0,length/2);
const res2 = string.slice(length/2);
console.log(res1,res2);
Based on your request, I created the following piece of code :-)
Hope it helps.
var inputBox, warning, fBox, sBox;
function inputBoxChanged(e) {
var text = e.currentTarget.value;
if (text.length % 2 != 0) {
warning.innerText = "Value needs to be even sized";
fBox.value = "";
sBox.value = "";
} else {
warning.innerText = "";
var splitPos = text.length / 2;
fBox.value = text.slice(0, splitPos);
sBox.value = text.slice(splitPos, text.length);
}
}
document.addEventListener("DOMContentLoaded", function (e) {
inputBox = document.getElementById("input");
warning = document.getElementById("warning");
fBox = document.getElementById("first");
sBox = document.getElementById("second");
inputBox.addEventListener("change", inputBoxChanged);
});
<html>
<body>
<input id="input" type="text"/>
<span id="warning"></span>
<hr/>
<input id="first" type="text" readonly/>
<input id="second" type="text"readonly/>
</body>
</html>
Use substring() function as
var substring=string.substring(strating_index,end_index);
index will start from 0
var str="1234567890"
var substr=str.substring(0,str.length/2);
var substr2=str.substring(strlength/2,strlength);
$("#ID1").val(substr);
$('#ID2').val(substr2);
Fiddle - http://liveweave.com/enRy3c
Here's what I'm trying to do.
Say my input number is 5. I want to dynamically append 5 divs to the class .enfants. However I haven't figured out how to do that. I been searching and searching and I haven't came across anything.
jQuery/JavaScript:
var counter = 1;
// Value number = .enfants children
$(".ajouter-enfants").on('keyup change', function() {
var yourChildren = "<div>" + counter++ + "</div>";
var CallAppend = function() {
$(".enfants").append( yourChildren );
};
// If 0 or empty clear container
if ( $.inArray($(this).val(), ["0", "", " "]) > -1 ) {
$(".enfants").html("");
// If only add/have 1 div in container
} else if ($(this).val() === "1") {
$(".enfants").html("").append( yourChildren );
// If > 0 add as many divs as value says
} else {
$(".enfants").html("");
CallAppend();
}
});
HTML:
<div class="contenu" align="center">
<div>
Value number = .enfants children
</div>
<input type="number" min="0" class="ajouter-enfants" value="0" />
<div class="enfants">
</div>
</div>
How about a simple loop? If you just want to append, try something like this:
$(".ajouter-enfants").on('change', function() {
var numDivs = $(this).val();
var i;
for (i = 1; i <= numDivs; i += 1) {
$('.enfants').append('<div>' + i + '</div>');
}
});
EDIT:
If you want to replace instead of append the newly-created <div>'s, try something like:
$(".ajouter-enfants").on('keyup change', function() {
var content = '';
var numDivs = $(this).val();
var i;
for (i = 1; i <= numDivs; i += 1) {
content += '<div>' + i + '</div>';
}
$('.enfants').html(content);
});
This will replace the entire content of any elements using the class ajouter-enfants with the number of <div>'s specified in the input box.
Try this:
$(".ajouter-enfants").on('keyup change', function() {
var num = +$.trim($(this).val()), target = $(".enfants"), i = 0, s = '';
target.empty();
if (!isNaN(num) && num > 0) {
for (; i < num; i++) {
s += '<div>' + (i + 1) + '</div>';
}
target.html(s);
}
});
How would you get it to only append the value amount? It appends more when the value is (2 becomes 3, 3 becomes 6, 4 becomes 10 and repeats even when I'm decreasing the numeric value) –
#Michael Schwartz
Here is another code example that might be helpfull.
$(".ajouter-enfants").on('change', function() {
var numDivs = $(this).val();
var i;
var html ='';
for (i = 1; i <= numDivs; i += 1) {
html += '<div>' + i + '</div>';
}
$('.enfants').empty().append(html);
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="contenu" align="center">
<div>
Value number = .enfants children
</div>
<input type="number" min="0" class="ajouter-enfants" value="0" />
<div class="enfants">
</div>
</div>
I want to be able to enter a number into a text box and then on a button click generate that number of text boxes in another div tag and automatically assign the id
Something like this but not sure how to generate the text boxes and assign automatically assign the id
function textBox(selections) {
for (i=0; i < selections +1; i++) {
document.getElementById('divSelections').innerHTML = ("<form><input type="text" id="1" name=""><br></form>");
}
}
Try this one:
function textBox(selections){
selections = selections*1; // Convert to int
if( selections !== selections ) throw 'Invalid argument'; // Check NaN
var container = document.getElementById('divSelections'); //Cache container.
for(var i = 0; i <= selections; i++){
var tb = document.createElement('input');
tb.type = 'text';
tb.id = 'textBox_' + i; // Set id based on "i" value
container.appendChild(tb);
}
}
A simple approach, which allows for a number to be passed or for an input element to be used:
function appendInputs(num){
var target = document.getElementById('divSelections'),
form = document.createElement('form'),
input = document.createElement('input'),
tmp;
num = typeof num == 'undefined' ? parseInt(document.getElementById('number').value, 10) : num;
for (var i = 0; i < num; i++){
tmp = input.cloneNode();
tmp.id = 'input_' + (i+1);
tmp.name = '';
tmp.type = 'text';
tmp.placeholder = tmp.id;
form.appendChild(tmp);
}
target.appendChild(form);
}
Called by:
document.getElementById('create').addEventListener('click', function(e){
e.preventDefault();
appendInputs(); // no number passed in
});
JS Fiddle demo.
Called by:
document.getElementById('create').addEventListener('click', function(e){
e.preventDefault();
appendInputs(12);
});
JS Fiddle demo.
The above JavaScript is based on the following HTML:
<label>How many inputs to create:
<input id="number" type="number" value="1" min="0" step="1" max="100" />
</label>
<button id="create">Create inputs</button>
<div id="divSelections"></div>
See below code sample :
<asp:TextBox runat="server" ID="textNumber"></asp:TextBox>
<input type="button" value="Generate" onclick="textBox();" />
<div id="divSelections">
</div>
<script type="text/javascript">
function textBox() {
var number = parseInt(document.getElementById('<%=textNumber.ClientID%>').value);
for (var i = 0; i < number; i++) {
var existingSelection = document.getElementById('divSelections').innerHTML;
document.getElementById('divSelections').innerHTML = existingSelection + '<input type="text" id="text' + i + '" name=""><br>';
}
}
</script>
Note: Above code will generate the N number of textboxes based on the number provided in textbox.
It's not recommended to user innerHTML in a loop :
Use instead :
function textBox(selections) {
var html = '';
for (i=0; i < selections +1; i++) {
html += '<form><input type="text" id="'+i+'" name=""><br></form>';
}
document.getElementById('divSelections').innerHTML = html;
}
And be carefull with single and double quotes when you use strings
You have to change some code snippets while generating texboxes, Learn use of + concatenate operator, Check code below
function textBox(selections) {
for (var i=1; i <= selections; i++) {
document.getElementById('divSelections').innerHTML += '<input type="text" id="MytxBox' + i + '" name=""><br/>';
}
}
textBox(4); //Call function
JS Fiddle
Some points to taken care of:
1) In for loop declare i with var i
2) your selection + 1 isn't good practice at all, you can always deal with <= and < according to loop's staring variable value
3) += is to append your new HTML to existing HTML.
ID should be generate manually.
var inputName = 'divSelections_' + 'text';
for (i=0; i < selections +1; i++) {
document.getElementById('divSelections').innerHTML = ("<input type='text' id= " + (inputName+i) + " name=><br>");
}
edit : code formated
Instead of using innerHTML, I would suggest you to have the below structure
HTML:
<input type="text" id="id1" />
<button id="but" onclick="addTextBox(this)">click</button>
<div id="divsection"></div>
JS:
function addTextBox(ops) {
var no = document.getElementById('id1').value;
for (var i = 0; i < Number(no); i++) {
var text = document.createElement('input'); //create input tag
text.type = "text"; //mention the type of input
text.id = "input" + i; //add id to that tag
document.getElementById('divsection').appendChild(text); //append it
}
}
JSFiddle