我想写一个正则表达式来匹配用单引号括起来的字符串，但不应该匹配用双引号括起来的单引号的字符串。
示例 1：
a = 'This is a single-quoted string';
a 的整个值应该匹配，因为它是用单引号括起来的。
编辑：完全匹配应该是： '这是一个单引号字符串'
示例 2：
x = "This is a 'String' with single quote";
x 不应返回任何匹配项，因为单引号位于双引号内。
我试过 /'.*'/g 但它也匹配双引号字符串中的单引号字符串。
感谢您的帮助！
编辑：
为了更清楚
给定以下字符串：
The "quick 'brown' fox" jumps
over 'the lazy dog' near
"the 'riverbank'".
匹配应该只有：
'the lazy dog'
【问题讨论】：
标签： javascript regex string
【讨论】：
the whole value of a should match because it is enclosed with single quotes.
如果您不受正则表达式的严格限制，您可以使用函数“indexOf”来确定它是否是双引号匹配的子字符串：
var a = "'This is a single-quoted string'";
var x = "\"This is a 'String' with single quote\"";
singlequoteonly(x);
function singlequoteonly(line){
var single, double = "";
if ( line.match(/\'(.+)\'/) != null ){
single = line.match(/\'(.+)\'/)[1];
}
if( line.match(/\"(.+)\"/) != null ){
double = line.match(/\"(.+)\"/)[1];
}
if( double.indexOf(single) == -1 ){
alert(single + " is safe");
}else{
alert("Warning: Match [ " + single + " ] is in Line: [ " + double + " ]");
}
}
请参阅下面的 JSFiddle：
【讨论】：
假设不必处理转义引号（这是可能的，但会使正则表达式变得复杂），并且所有引号都正确平衡（不像It's... "Monty Python's Flying Circus"!），那么您可以查找单引号字符串后跟偶数个双引号：
/'[^'"]*'(?=(?:[^"]*"[^"]*")*[^"]*$)/g
说明：
' # Match a '
[^'"]* # Match any number of characters except ' or "
' # Match a '
(?= # Assert that the following regex could match here:
(?: # Start of non-capturing group:
[^"]*" # Any number of non-double quotes, then a quote.
[^"]*" # The same thing again, ensuring an even number of quotes.
)* # Match this group any number of times, including zero.
[^"]* # Then match any number of characters except "
$ # until the end of the string.
) # (End of lookahead assertion)
【讨论】：