常用javascript方法汇总

1. 将输入的全角数字全部转化成半角数字
function toSmall(v,evt){

//为了兼容ie和firefox,ie中获取keyCode方法是evt.keyCode，firefox中是evt.which
var k=window.event?evt.keyCode:evt.which;
if((k>47 && k<58)||(k>95 && k<106)){
var t = '';
with(v.value) {
for (var i = 0; i < length; i++)
t += (65296 <= charCodeAt(i) && charCodeAt(i) <= 65305) ? String.fromCharCode(charCodeAt(i) - 65248) : charAt(i);
}
v.value = t;
};
}



<html:text property="phone" onkeyup="javascript:toSmall(this,event);" />



2. 获取字符串的长度(1个汉字算2个字节)

function getStrLength(sString) {
var j = 0;
var s = sString;
if (s=="") return j;
for (var i=0; i<s.length; i++)
{
if (s.substr(i,1).charCodeAt(0)>255) j = j + 2;
else j++
}

return j;
}