js之concat()_join()

/*concat()结果返回的是一个数组*/

var arr = new Array(3)
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"

var arr2 = new Array(3)
arr2[0] = "James"
arr2[1] = "Adrew"
arr2[2] = "Martin"

document.write(arr.concat(arr2))


//result:
George,John,Thomas,James,Adrew,Martin

/*join()返回的是一个字符串*/
var arr = new Array(3);
arr[0] = "George"
arr[1] = "John"
arr[2] = "Thomas"

document.write(arr.join());

document.write("<br />");

document.write(arr.join("."));
//result:
George,John,Thomas
George.John.Thomas