javascript 日期<---->字符串 转换函数

 

/*将String类型解析为Date类型.    
  parseDate('2006-1-1') return new Date(2006,0,1)    
  parseDate(' 2006-1-1 ') return new Date(2006,0,1)    
  parseDate('2006-1-1 15:14:16') return new Date(2006,0,1,15,14,16)    
  parseDate(' 2006-1-1 15:14:16 ') return new Date(2006,0,1,15,14,16);    
  parseDate('2006-1-1 15:14:16.254') return new Date(2006,0,1,15,14,16,254)    
  parseDate(' 2006-1-1 15:14:16.254 ') return new Date(2006,0,1,15,14,16,254)    
  parseDate('不正确的格式') retrun null    
*/     
function parseDate(str){      
  if(typeof str == 'string'){      
    var results = str.match(/^ *(\d{4})-(\d{1,2})-(\d{1,2}) *$/);      
    if(results && results.length>3)      
      return new Date(parseInt(results[1]),parseInt(results[2]) -1,parseInt(results[3]));       
    results = str.match(/^ *(\d{4})-(\d{1,2})-(\d{1,2}) +(\d{1,2}):(\d{1,2}):(\d{1,2}) *$/);      
    if(results && results.length>6)      
     return new Date(parseInt(results[1]),parseInt(results[2]) -1,parseInt(results[3]),parseInt(results[4]),parseInt(results[5]),parseInt(results[6]));       
    results = str.match(/^ *(\d{4})-(\d{1,2})-(\d{1,2}) +(\d{1,2}):(\d{1,2}):(\d{1,2})\.(\d{1,9}) *$/);      
    if(results && results.length>7)      
      return new Date(parseInt(results[1]),parseInt(results[2]) -1,parseInt(results[3]),parseInt(results[4]),parseInt(results[5]),parseInt(results[6]),parseInt(results[7]));       
  }      
  return null;      
}      

/*    
  将Date/String类型,解析为String类型.    
  传入String类型,则先解析为Date类型    
  不正确的Date,返回 ''    
  如果时间部分为0,则忽略,只返回日期部分.    
*/     
function formatDate(v){      
  if(typeof v == 'string') v = parseDate(v);      
  if(v instanceof Date){      
    var y = v.getFullYear();      
    var m = v.getMonth() + 1;      
    var d = v.getDate();      
    var h = v.getHours();      
    var i = v.getMinutes();      
    var s = v.getSeconds();      
    var ms = v.getMilliseconds();         
    if(ms>0) return y + '-' + m + '-' + d + ' ' + h + ':' + i + ':' + s + '.' + ms;      
    if(h>0 || i>0 || s>0) return y + '-' + m + '-' + d + ' ' + h + ':' + i + ':' + s;      
    return y + '-' + m + '-' + d;      
  }      
  return '';      
}