1.字符串参与判断时:非空即为真判断字符串为空的方法if(str!=null && str!=undefined && str !='')可简写为if(!str){ console.log(str)}2.数字参与if判断:非0非NAN即为真 var i = 0;if(i){ alert('here');}else{ alert('test is ok!');} 输出结果为here var i = 0;if(i){ alert('here');}else{ alert(
angela@angeladeMacBook-Air:/data/db$mongo MongoDB shell version: 2.6.1 connecting to: test 2014-06-07T11:13:21.349+0800 warning: Failed to connect to 127.0.0.1:27017, reason: errno:61 Connection refused 2014-06-07T11:13:21.350+0800 Error: couldn't co
POJ 3286 How many 0's?(几多0?) Time Limit: 1000MS Memory Limit: 65536K [Description] [题目描述] A Benedict monk No.16 writes down the decimal representations of all natural numbers between and including m and n, m ≤ n. How many 0's will he write down? 一个