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<SCRIPT LANGUAGE="JavaScript">
( k. Z" A: ?: |2 I$ p. J/ f<!-- Begin5 ^4 B% u+ n' Z* d" |" L4 n5 Z: c
function calculate(form) {
0 Z/ K. _# v A4 Dvar num=parseInt(form.number.value);, M: ]; J% L3 ~4 Z
if (isNaN(num) || num < 0) {
! H& J4 E% d4 Q# g% ]- Oform.result.value=(form.number.value + " is not a valid number! Try again!");
* [9 Z. g1 ~( b! p" f. V0 i}1 K- o' E! M" E* _% m/ o& s
if (num == 1 || num == 2) {4 l$ V, E0 b5 Q# {8 d% D; p1 Q
form.result.value=(num + " is prime!");
1 G+ E" m' ^5 W% O! T2 M} w, \ ~' [% P; l! Q! e
for (var i=2;i<num;i++) {
2 O' F* ?* H: F" _& ?2 ]if (num % i == 0) {
7 {8 j8 U" V; g8 E, Evar prime="yes";
# c- @! @, f* A \" jform.result.value=(num + "不是素数,它能被" + i + "整除.");
* ^7 i) g: M! b& X7 Gbreak;- K4 b4 T$ p- S% b7 x, q4 V" ?8 ?; ]
}
! i/ ]1 R, \& aif (num % i != 0) var prime="no";+ W: [1 E. v+ h/ K4 [3 E
}' a+ b' O# T6 p. b5 t
if (prime == "no") form.result.value=(num + "是素数");. a P" b& f. ~
}
. T7 {% {+ K- L0 b a" _// End -->5 O! P9 o; [% Q( _, @& l" I) ~
</SCRIPT>
5 S' G- T9 D! Z: b1 W<form name=form> s) s/ _ x ]7 p% v
<h2>素数检测</h2><p>4 M7 e X8 W# S9 G
请输入一个数:<br>
! g7 |& P0 y* i: n F6 |<input type=text name=number size=7>) o3 d% Z$ O* k; }0 b( W
<input type=button value="Calculate" onClick="calculate(this.form)">. c' w! E/ H) l! i' X
< >
1 t4 c+ W$ Y7 H4 V9 T<input type=text name=result size=45 value="">5 x- t. |5 v3 v- F% _% E, L
</form> 一段检测素数的JS代码实例! |