|
<SCRIPT LANGUAGE="JavaScript">
* S% n9 A, w0 P4 s. u8 ], ?<!-- Begin: a3 [% Q5 [: e, z% e& g
function calculate(form) {
) L' I7 U( i/ q' {var num=parseInt(form.number.value);
, ]; U9 R( P9 W$ Y4 x% zif (isNaN(num) || num < 0) {
! K( s% F; b* }/ Q0 Eform.result.value=(form.number.value + " is not a valid number! Try again!");
) U. w. R6 r# S+ X `1 W' V) s}9 S3 P3 m. D/ P3 q9 S+ J
if (num == 1 || num == 2) {! ~+ l. ]& B8 s% p m. x- J
form.result.value=(num + " is prime!");, p9 {/ B1 x( `: Y2 d& ?( q$ R# `3 W
}
6 W/ q( z- i# B9 R# H: Vfor (var i=2;i<num;i++) {* A2 V/ T" M6 w( r5 @: o9 S3 |
if (num % i == 0) {* {: L, `( Q2 z% f
var prime="yes";* m, Q! i+ `2 ?2 L* x
form.result.value=(num + "不是素数,它能被" + i + "整除.");
- a/ y% E k& e& C" _: }5 `break; I9 w' w6 Y9 [' e6 T
}" Q; h9 ]) w8 W2 N
if (num % i != 0) var prime="no";7 C7 E5 K, g7 c# N/ P# U* V
}* E, L8 U0 U) J$ U8 }# j0 H: ?
if (prime == "no") form.result.value=(num + "是素数");: n8 ]4 K$ z5 N# `
}
6 L2 v, X7 f& U// End -->
7 o C4 ?8 M5 C: R6 F4 l</SCRIPT>0 d: p. t8 K+ d7 s# w* t6 I' x8 V
<form name=form>$ ~8 y2 x9 H# s! N" U
<h2>素数检测</h2><p>
5 Z: H5 r, X; w' x0 l2 c请输入一个数:<br>
/ U g7 E8 l3 a: u) X<input type=text name=number size=7>
6 f; r; D- l; V, c; s% p<input type=button value="Calculate" onClick="calculate(this.form)">" @. Y6 V B! I" l# c
< >' h$ h' H4 x! A& G! ?# _
<input type=text name=result size=45 value="">
' o8 O8 k1 R. ^! n</form> 一段检测素数的JS代码实例! |