<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title> 验证数字最简单正则表达式大全 </title> </head> <body> <h3>输入完按回车后即可验证！（自认为最简单！）</h3> 正整数: <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^\d+$/.test(this.value));" /> <br> 负整数: <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-\d+$/.test(this.value));" /> <br> 整 数: <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-?\d+$/.test(this.value));" /> <br> 正小数: <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^\d+\.\d+$/.test(this.value));" /> <br> 负小数: <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-\d+\.\d+$/.test(this.value));" /> <br> 小 数: <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-?\d+\.\d+$/.test(this.value));" /> <br> 实 数: <input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-?\d+\.?\d*$/.test(this.value));" /> <br> 保留1位小数:<input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-?\d+\.?\d{0,1}$/.test(this.value));" /> <br> 保留2位小数:<input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-?\d+\.?\d{0,2}$/.test(this.value));" /> <br> 保留3位小数:<input type="text" size="20" onkeydown="if(event.keyCode == 13) alert(/^-?\d+\.?\d{0,3}$/.test(this.value));" /> <br> </body> </html>