number_format for javascript

number_format.js

function number_format(num, precision, glue){
	num = parseFloat(num);
	
	if(isNaN(num))
	    num = 0;
	
	precision = (!precision || isNaN(precision = parseInt(precision))) ? 2 : precision;
	num = num.toFixed(precision);
	glue = glue ? glue : ",";
	
	num = num.replace(/^(\d+)\.?/, function(match, p1){
	    var len = p1.length;
	    var i=len-4;// 初始位置
	    var trim = (match.length === len);
	    for(;i > -1;i -= 3){
	        p1 = p1.substr(0, i+1) + glue + p1.substr(i+1);
	    }
	    return p1 + (trim ? "" : ".");
	});
	
	return num;
}