C/c++,java,php,javascript,json array, object assignment, can the last element be followed by a comma?

1 c,c++,java,php can tolerate the comma at the end.

When assigning a value to an array in C,c++,java, the comma at the end of the last element is optional. The following two lines of code are equivalent to these languages.

int a[] = {1,2,3};      /* 正确 */int a[] = {1,2,3,};     /* 正确 */

PHP also inherits the characteristics of C, the following two lines of code are equivalent.

$aarray(1,2,3/* 正确 */$aarray(1,2,3/* 正确 */

2 JavaScript view end comma is a syntax error!

However, in JavaScript, the situation is very different, the last element must not have a comma at the end, otherwise it is a syntax error.

varnewArray(1,2,3//正确varnewArray(1,2,3//报错

For an object, you also cannot have a comma at the end.

var o = { name:‘赵‘, age:12// 正确var o = { name:‘赵‘, age:12// 报错

Although some browsers implement the maximum tolerance after detecting this error, this is not a uniform behavior. IE series browsers do not tolerate this error.

3 JSON also does not tolerate the comma at the end

{"name":"zhao""age":12}   // 正确的JSON格式{"name":"zhao""age":12,}  // 错误的JSON格式

It is important to note that JSON is a common data format that is independent of the specific programming language. Various languages also use different levels of tolerance when decoding JSON. PHP Json_decode () will not tolerate the comma at the end.

json_decode({"name":"zhao", "age":12,})// 解析会发生错误

C/c++,java,php,javascript,json array, object assignment, can the last element be followed by a comma?