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<SCRIPT LANGUAGE="JavaScript">* g! }+ c! F. `* S/ M4 ^
<!-- Begin
" O# M) v9 B3 [: }: |function calculate(form) {
; b( a7 O" Y: xvar num=parseInt(form.number.value);
5 {* T$ a2 I9 C8 Tif (isNaN(num) || num < 0) {) Q# h, _) O- D( t- g [+ e
form.result.value=(form.number.value + " is not a valid number! Try again!");
, ?+ _ v. ^% R Q# X}! M. n4 z9 E7 E+ v) D/ b
if (num == 1 || num == 2) {
. v/ w. m) f# Q6 C& gform.result.value=(num + " is prime!");
& u- y$ c( I4 H}
; r0 D+ h, I6 Hfor (var i=2;i<num;i++) {
4 R6 w( v. a3 r. ^% Zif (num % i == 0) {, U( I# n( w$ F8 c! ~; W; I3 P
var prime="yes";/ w" S+ i# e3 [8 t
form.result.value=(num + "不是素数,它能被" + i + "整除.");
5 b# W4 F3 M3 a$ k1 b0 L7 qbreak;; w% N/ ~3 Z8 m& C/ q+ v3 \3 O
}- ^* V$ j7 p- H$ y4 D
if (num % i != 0) var prime="no";
7 n" C4 ^' G4 M+ I2 |6 o}, c$ C) H* @3 p* f6 Q& `
if (prime == "no") form.result.value=(num + "是素数");
& p7 d; s% M( D* y: c, N} 3 B$ S0 E; f7 S, b3 p! Z0 a# e
// End -->; R$ h) o( }* t0 Y8 ^; I& |6 E
</SCRIPT>
, ]' L* ^$ W% }0 u# [! n8 K<form name=form># v" I1 M7 A @$ G: h
<h2>素数检测</h2><p>9 ^% l' g( p% Z7 c/ R7 J+ T6 O
请输入一个数:<br>3 J2 q3 ~( u8 E' R8 c
<input type=text name=number size=7>7 v( N6 d! L: j) E( V; [& L$ d1 Q
<input type=button value="Calculate" onClick="calculate(this.form)">3 P0 Z5 u& m7 L" ~8 v: s2 n
< >- T: j0 v) G6 D+ q7 \# S
<input type=text name=result size=45 value="">
B* N' W k. m* k</form> 一段检测素数的JS代码实例! |