I have the following HTML5 input element:
<input type="number">
Why does this input allow for the character 'e' to be entered in the input field? No other alphabet character is able to be entered (as expected)
Using Chrome v. 44.0.2403.107
Example below to see what I mean.
<input type="number">
Because that's exactly how the spec says it should work. The number input can accept floating-point numbers, including negative symbols and the e or E character (where the exponent is the number after the e or E):
A floating-point number consists of the following parts, in exactly the following order:
- Optionally, the first character may be a "
-" character.- One or more characters in the range "
0—9".- Optionally, the following parts, in exactly the following order:
- a "
." character- one or more characters in the range "
0—9"- Optionally, the following parts, in exactly the following order:
- a "
e" character or "E" character- optionally, a "
-" character or "+" character- One or more characters in the range "
0—9".
We can make it So simple like below
<input type="number" onkeydown="javascript: return event.keyCode == 69 ? false : true" />Updated Answer
we can make it even more simple as @88 MPG suggests
<input type="number" onkeydown="return event.keyCode !== 69" />
The best way to force the use of a number composed of digits only:
<input type="number" onkeydown="javascript: return ['Backspace','Delete','ArrowLeft','ArrowRight'].includes(event.code) ? true : !isNaN(Number(event.key)) && event.code!=='Space'" />To allow number keys only, convert to number with Number function. If this is not a number, the result is NaN :
isNaN(Number(event.key))
but accept Backspace, Delete, Arrow left, Arrow right :
['Backspace','Delete','ArrowLeft','ArrowRight'].includes(event.code)
This is for Firefox which allows spaces :
event.code!=='Space'
HTML input number type allows "e/E" because "e" stands for exponential which is a numeric symbol.
Example 200000 can also be written as 2e5. I hope this helps thank you for the question.
<input type="number" onkeydown="return FilterInput(event)" onpaste="handlePaste(event)" >
function FilterInput(event) {
var keyCode = ('which' in event) ? event.which : event.keyCode;
isNotWanted = (keyCode == 69 || keyCode == 101);
return !isNotWanted;
};
function handlePaste (e) {
var clipboardData, pastedData;
// Get pasted data via clipboard API
clipboardData = e.clipboardData || window.clipboardData;
pastedData = clipboardData.getData('Text').toUpperCase();
if(pastedData.indexOf('E')>-1) {
//alert('found an E');
e.stopPropagation();
e.preventDefault();
}
};
A simple solution to exclude everything but integer numbers
<input
type="number"
min="1"
step="1"
onkeypress="return event.keyCode === 8 || event.charCode >= 48 && event.charCode <= 57">This solution does not prevent copy and pasting (including the letter 'e').
To hide both letter e and minus sign - just go for:
onkeydown="return event.keyCode !== 69 && event.keyCode !== 189"
Using angular, You can do this to restrict to enter e,+,-,E
<input type="number" (keypress)="numericOnly($event)"/>
numericOnly(event): boolean { // restrict e,+,-,E characters in input type number
debugger
const charCode = (event.which) ? event.which : event.keyCode;
if (charCode == 101 || charCode == 69 || charCode == 45 || charCode == 43) {
return false;
}
return true;
}
The E stands for the exponent, and it is used to shorten long numbers. Since the input is a math input and exponents are in math to shorten great numbers, so that's why there is an E.
It is displayed like this: 4e.
<input type="number" oninput="this.value = this.valueAsNumber">
The above solutions work in regular html only. For reactJS I would suggest you to do this instead
<input type="number" onKeyDown={(e) =>["e", "E", "+", "-"].includes(e.key) && e.preventDefault()} >
if you hit a key and its computer language equivalent is 69 it won't type it
<input
type="number"
onkeydown="return event.keyCode !== 69"
/>
The functionally is the same as rinku's answer but with IDE warning prevention
numericOnly(event): boolean {
// noinspection JSDeprecatedSymbols
const charCode = (event.which) ? event.which : event.key || event.keyCode; // keyCode is deprecated but needed for some browsers
return !(charCode === 101 || charCode === 69 || charCode === 45 || charCode === 43);
}
Simple and standard solution : In Angular/ Js/ Ts you can use regular expression to restrict any input key.
HTML: <input type="text" name="input1" (keypress)="numericOnly($event)" />
TS:
numericPattern = /^[0-9]*$/;
numericOnly(event){
return this.numericPattern.test(event.key);
}
<input type="number" onkeyup="this.value = parseInt(this.value); this.paste(this.onkeyup);"/>
ParseInt() returns blank(NaN) for E, e, +, - and anything which is not a number.
Use onkeyup and keydown according to your convenience with paste event. For me onkeyup works best. This works with copy-paste as well
<input type="number" onkeydown="javascript: return ['Backspace','Delete','ArrowLeft','ArrowRight'].includes(event.code) ? true : !isNaN(Number(event.key)) && event.code!=='Space'" />