compare two input values in input validation html javascript?
Question
I want to compare two inputs minimumN and maximumN, and display an alert if the logic is not satisfied, I have the following code:
HTML:
<table>
<tr>
<th>Minimum N</th>
<td>
<input id="minN" onkeyup="MinimumNValidate()" type="text" maxlength="50">
</td>
<th>Maximum N</th>
<td>
<input id="maxN" onkeyup="MaximumNValidate()" type="text" maxlength="50">
</td>
</tr>
</table>
Javascript:
function MinimumNValidate() {
var min = document.getElementById("minN").value;
var max = document.getElementById("maxN").value;
if (min > max) {
alert("Minimum value must be lesser than maximum value.");
}
}
function MaximumNValidate() {
var min = document.getElementById("minN").value;
var max = document.getElementById("maxN").value;
if (max < min) {
alert("Maximum value must be greater than minimum value.");
}
}
but this is not working, and the alert is being displayed even when the minN is less than maxN, can you point out the mistake in my code ?
3 answers
solution1
4 ACCPTED 2013-09-20 20:35:15
Few things here
close the input elements:
if(maxN<min) {
Should be
if(max<min) {
Finally, you are not comparing integers but strings so..
5<9
555<9
1000<20
Its "alphabetic"
You need to parse them to int.
parseInt(max) and parseInt(min)
...
function MinimumNValidate(){
var min = parseInt(document.getElementById("minN").value);
var max = parseInt(document.getElementById("maxN").value);
if(min > max) {
alert("Minimum value must be lesser than maximum value. " + min + " > " + max );
}
}
function MaximumNValidate(){
var min = parseInt(document.getElementById("minN").value);
var max = parseInt(document.getElementById("maxN").value);
if(max<min) {
alert("Maximum value must be greater than minimum value." + min + " > " + max );
}
}
solution2
3 2013-09-20 20:02:29
In the second function MaximumNValidate(), you have the line of code
if(maxN<min) {
which should be
if(max<min) {
solution3
1 2019-11-20 14:48:49
function checknumber(theForm) { if (parseInt(theForm.num2.value) != (parseInt(theForm.num1.value)+1)) { alert('enter the correct year in intermediate'); return false; } return true; }
<!doctype html> <head> </head> <body> <form action="../" onsubmit="return checknumber(this);"> <label> tenth graduation </label> <input type="number" name="num1" autocomplete="off"><br> <br> <label> Intermediate </label> <input type="number" name="num2" autocomplete="off"> <input type="SUBMIT" value="year validation"> </form>
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.