正则表达式-Javascript捕获区域

Question

I want to capture only a area of the Match part. I have following String: " type1-class1 type1-class2 type2-class4 type2-type1-class3 " and i want following result ["class1", "class2"] . I am searching the class by the type . I have tried following:

 console.log(" type1-class1 type1-class2 type2-class4 type2-type1-class3 ".match(/\\btype1-.*?(?= )/g)) // Result: ["type1-class1", "type1-class2", "type1-class3"] 

Furthermore i have tried following:

 console.log(" type1-class1 type1-class2 type2-class4 type2-type1-class3 ".match(/(?= type1-).*?(?= )/g)); // Result: ["", ""] 

How can i disable the capture on the beginning of a Regex?

Answer 1

I'd use an exec loop. The regular expression is /(?:^|\\s)type1-([^ ]+)/g , eg, "Following a type-1 that's at the beginning of the string or just after whitespace, capture everything until the next whitespace or end of string. (With your string as given, we don't need the alternation with ^ , but I wanted to allow for "type1-class1" at beginning of string.) We then collect the captures in a loop:

 var rex = /(?:^|\\s)type1-([^ ]+)/g; var str = " type1-class1 type1-class2 type2-class4 type2-type1-class3 "; var classes = []; var m; while ((m = rex.exec(str)) != null) { classes.push(m[1]); } console.log(classes); 

Answer 2

这是您所期望的吗？

console.log(" type1-class1 type1-class2 type2-class4 type2-type1-class3 ".match(/ type1-.*?(?= )/g).map(x=>x.replace(/type1-/g,"").trim()))