<!DOCTYPE html>
<
html
lang
=
"en"
>
<
head
>
<
title
>
detect the duplication of
values of input fields
</
title
>
</
head
>
<
body
>
<
label
>Phone no. 1</
label
>
<
input
id
=
"gfg_field0"
/>
<
div
id
=
"status0"
></
div
>
<
label
>Phone no. 2</
label
>
<
input
id
=
"gfg_field1"
/>
<
div
id
=
"status1"
></
div
>
<
label
>Phone no. 3</
label
>
<
input
id
=
"gfg_field2"
/>
<
div
id
=
"status2"
></
div
>
<
label
>Phone no. 4</
label
>
<
input
id
=
"gfg_field3"
/>
<
div
id
=
"status3"
></
div
>
<
br
>
<
button
type
=
"submit"
onclick
=
"gfg_check_duplicates()"
>
Check for Duplicates !
</
button
>
<
script
>
function gfg_check_duplicates() {
let myarray = [];
for (i = 0; i <
4
; i++) {
document.getElementById("status" + i)
.innerHTML
=
""
;
myarray[i] =
document.getElementById("gfg_field" + i)
.value;
}
for (
i
=
0
; i < 4; i++) {
let
flag
=
false
;
for (
j
=
0
; j < 4; j++) {
if (i == j || myarray[i] == "" || myarray[j] == "")
continue;
if (myarray[i] == myarray[j]) {
flag
=
true
;
document.getElementById("status" + i)
.innerHTML +=
"<br>Its identical to the phone number " + (j + 1);
}
}
if (flag == false)
document.getElementById("status" + i)
.innerHTML = "";
}
}
</
script
>
</
body
>
</
html
>