獲取匹配行

Question

下面是我有的示例字符串。

143s: WHAT IS <span>THAT</span>? 144s: HEAR THAT? 152s: EVERYBODY, SHH. SHH. 156s: <span>STAY</span> UP THERE. 163s: [BOAT CREAKING] 165s: WHAT IS THAT? 167s: [SCREAMING] 191s: COME ON! 192s: OH, GOD! 193s: AAH! 249s: OK. WE'VE HAD SOME PROBLEMS 253s: AT THE FACILITY. 253s: WHAT WE'RE ATTEMPTING TO <span>ACHIEVE</span> 256s: HERE HAS <span>NEVER</span> BEEN DONE. 256s: WE'RE THIS CLOSE 259s: TO THE REACTIVATION 259s: OF A HUMAN BRAIN CELL. 260s: DOCTOR, THE 200 MILLION 264s: I'VE SUNK INTO THIS COMPANY 264s: IS DUE IN GREAT PART 266s: TO YOUR RESEARCH.

考慮，串ns:和文字，之後，作爲一個單一的線。

例如259s: OF A HUMAN BRAIN CELL.

我需要的正則表達式，返回我行有，

Previous Line of Line having span tag if any + Line having span tag + Next Line of having span tag if any 

所以上面的字符串應該返回我的3場比賽。

1st : 143s: WHAT IS <span>THAT</span>? 144s: HEAR THAT? 
2nd : 152s: EVERYBODY, SHH. SHH. 156s: <span>STAY</span> UP THERE. 163s: [BOAT CREAKING] 
3rd : 253s: WHAT WE'RE ATTEMPTING TO <span>ACHIEVE</span> 256s: HERE HAS <span>NEVER</span> BEEN DONE 

Answer 1

「有上線...」是需要lookbehind，這是不被JS所支持的條件。但是，正則表達式會過於複雜，因此只需解析它並循環查看匹配的行。

var text = "…"; 

var lines = [], 
    textparts = text.split(/(\d+s:)/); 
for (var i=1; i<textparts.length; i+=2) 
    lines[(i-1)/2] = { 
     lineNumber: textparts[i].match(/\d+/)[0], 
     text: textparts[i+1], 
     hasSpan: /<span>/.test(textparts[i+1]) 
    }; 
var matchedlines = []; 
for (var i=0; i<lines.length; i++) 
    if (lines[i-1] && lines[i-1].hasSpan && lines[i].hasSpan && …) // or whatever 
     matchedlines.push(lines[i]);