用逗号分隔字符串,但忽略引号内的逗号

Question

示例字符串:

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

这里我们用引号分隔4个引号值.

当我这样做:

str.split(',').forEach(…

比那还要分割"Bar, baz"我不想要的价值.是否可以使用正则表达式忽略引号内的逗号？

Answer 1

一种方法是在这里使用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

或者是否定的前瞻

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

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