~~~ //去除空格 type 1-所有空格 2-前后空格 3-前空格 4-后空格 function trim(str,type){ switch (type){ case 1:return str.replace(/\s+/g,""); case 2:return str.replace(/(^\s*)|(\s*$)/g, ""); case 3:return str.replace(/(^\s*)/g, ""); case 4:return str.replace(/(\s*$)/g, ""); default:return str; } } trim('a a dd ',1); // "aadd" trim('a a dd ',2); // "a a dd" trim('a a dd ',3); // "a a dd " trim(' a a dd ',4); // " a a dd" ~~~