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<SCRIPT LANGUAGE="JavaScript">- _4 n. ]9 y) }1 q2 D0 U6 @! v8 S
<!-- Begin
4 v# I, n7 V7 y8 `# }0 Ffunction calculate(form) {- d2 ` t1 _4 t2 {& X1 m
var num=parseInt(form.number.value);9 b' m# B# D* j% F% p, |
if (isNaN(num) || num < 0) {
4 W) z7 ]- R3 z$ S# {) P5 y+ S- O- wform.result.value=(form.number.value + " is not a valid number! Try again!");% p: [+ A. S& G5 v8 m+ X! g" H$ q# ~
}
" t, F) K3 O" `# V S. q" Bif (num == 1 || num == 2) {. Z' i9 H# I* x2 f M" W
form.result.value=(num + " is prime!");' v/ {2 `% {% z! X: O1 u
}: n* W Z1 _7 `/ ^* x8 g
for (var i=2;i<num;i++) {; [# v" B; Z0 P# O) Z
if (num % i == 0) {9 u3 \: O; Q" z
var prime="yes";6 e+ t) Y( f$ P- w. K: p
form.result.value=(num + "不是素数,它能被" + i + "整除.");
1 `: `' t+ _4 Dbreak;
2 C# V1 L" U( [; F2 G}
8 {; S1 g* a# N, Qif (num % i != 0) var prime="no";7 S7 s( m* b. s* a/ B1 @
}* a4 _) ^% @7 l3 O
if (prime == "no") form.result.value=(num + "是素数");9 e3 b1 U, c9 c' u+ m& D) r9 q6 F
}
; b* O0 a* T9 U' c// End -->* M: D2 S, k/ Y
</SCRIPT>, K/ ]" i' c( q! q+ T5 Q
<form name=form>
/ c$ |4 R; O0 h<h2>素数检测</h2><p>
9 j! A2 S9 ^( \4 J请输入一个数:<br>
f+ G$ \7 q: L<input type=text name=number size=7>
6 p! l2 ~# I* K) g<input type=button value="Calculate" onClick="calculate(this.form)">
! Q, h8 W# y9 y3 D/ |' d1 K< >
5 D1 j" E; C: g<input type=text name=result size=45 value="">
$ n9 {& u# l+ h( u</form> 一段检测素数的JS代码实例! |