var a = 'a b c d e f';
去除全部空格: var c= a.replace(/\s*/g,"");
去除两头空格: var c= a.replace(/^\s*|\s*$/g,"");
去除左空格: var c= a.replace( /^\s*/, “”);
去除右空格: var c= a.replace(/(\s*$)/g, "");
JQ也有个方法去除首尾空格,可是中间的空格会被保留
var a = ' asad fasff ' ;
$.trim(a)
https://blog.csdn.net/heshuaicsdn/article/details/80501441javascript