JS 字符串拼接

语法如下:

str.concat(string2[, string3, ..., stringN])


示例:

var hello = \'Hello, \';
console.log(hello.concat(\'Kevin\', \' have a nice day.\'));
/* Hello, Kevin have a nice day. */

var greetList = [\'Hello\', \' \', \'Venkat\', \'!\'];
"".concat(...greetList); // "Hello Venkat!"

"".concat({}); // [object Object]
"".concat([]); /// ""
"".concat(null); // "null"
"".concat(true); // "true"
"".concat(4, 5); // "45"
"".concat({}); // [object Object]