截取字符串:
Js代码varstr="1234567890";vara=str.substring(0,8);//==str.substring(8)---结果:12345678
var str = "1234567890";var a = str.substring(0,8); //==str.substring(8)---结果:12345678
显示当前期系统时间:
Js代码vartoday=newDate();varday=today.getDate();varmonth=today.getMonth()+1;//显示月份比实际月份小1,所以要加1varyear=today.getYear(); month=month<10?"0"+month:month;//数字<10,实际显示为,如5,要改成05 day=day<10?"0"+day:day;//和月份显示一样vardate=year+"-"+month+"-"+day;//结果:-05-08,-12-29
var today = new Date(); var day = today.getDate();var month = today.getMonth() + 1; //显示月份比实际月份小1,所以要加1var year = today.getYear();month = month<10?"0"+month:month; //数字<10,实际显示为,如5,要改成05day= day<10?"0"+day:day; //和月份显示一样var date = year + "-" + month + "-" + day;//结果:-05-08,-12-29
从文本框得到的数值计算:
Js代码varshu1=document.getElementById("shu1").value;//----2varshu2=document.getElementById("shu2").value;//----5varsum=parseInt(shu1)+parseInt(shu2);//要把得到文本框的值转成int,再加,否则直接加,会当成字符串,进行连接为25