用逗号分割字符串，但忽略引号内的逗号[重复]

Question

示例字符串：

"Foo","Bar, baz","Lorem","Ipsum"

这里我们有 4 个值，用逗号分隔。

当我这样做时：

str.split(',').forEach(…

这也会拆分我不想要的值"Bar, baz"。是否可以使用正则表达式忽略引号内的逗号？

Answer 1

一种方法是在此处使用 Positive Lookahead 断言。

var str = '"Foo","Bar, baz","Lorem","Ipsum"',
    res = str.split(/,(?=(?:(?:[^"]*"){2})*[^"]*$)/);

console.log(res);  // [ '"Foo"', '"Bar, baz"', '"Lorem"', '"Ipsum"' ]

正则表达式：

,               ','
(?=             look ahead to see if there is:
(?:             group, but do not capture (0 or more times):
(?:             group, but do not capture (2 times):
 [^"]*          any character except: '"' (0 or more times)
 "              '"'
){2}            end of grouping
)*              end of grouping
 [^"]*          any character except: '"' (0 or more times)
$               before an optional \n, and the end of the string
)               end of look-ahead

或负前瞻

var str = '"Foo","Bar, baz","Lorem","Ipsum"',
    res = str.split(/,(?![^"]*"(?:(?:[^"]*"){2})*[^"]*$)/);

console.log(res); // [ '"Foo"', '"Bar, baz"', '"Lorem"', '"Ipsum"' ]