JS判断文本输入内容是否为数字

第一种 1

OnKeyPress="if(((event.keyCode>=48)&&(event.keyCode <=57))) {event.returnValue=true;} else{event.returnValue=false;}"

 

如果输入的是数字则显示出来，， 否则不显示

 

第二种

 <script language="javascript" type="text/javascript">
        function keyPress(ob) {
            if (!ob.value.match(/^[\+\-]?\d*?\.?\d*?$/)) ob.value = ob.t_value; else ob.t_value = ob.value; if (ob.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/)) ob.o_value = ob.value;
        }
        function keyUp(ob) {
            if (!ob.value.match(/^[\+\-]?\d*?\.?\d*?$/)) ob.value = ob.t_value; else ob.t_value = ob.value; if (ob.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?)?$/)) ob.o_value = ob.value;
        }
        function onBlur(ob) {
         if(!ob.value.match(/^(?:[\+\-]?\d+(?:\.\d+)?|\.\d*?)?$/))ob.value=ob.o_value;else{if(ob.value.match(/^\.\d+$/))ob.value=0+ob.value;if(ob.value.match(/^\.$/))ob.value=0;ob.o_value=ob.value};
        }
        </script>

onkeypress="keyPress(this)" onkeyup="keyUp(this)" onblur="onBlur(this)"