Separate the contents of a variable via Regex

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In 2 variables I want to perform the following operations. In the 1st, var chat1, separate via regex 4 information: "To:", "How are you?", "B:" and "I’m fine, Thanks.", and be able to access them by their contents using the capture groups. And in the 2nd, var chat2, separate 2 pieces of information: "To:" and "How are you?". I understand little of regex and ended up not getting the expected results.

var chat1 = "A:How are you?B:I'm fine, thanks.";
var chat2 = "A:How are you?";

var c1 = chat1.match(/\b(A:)(.*?)(B:)(.*?)\b/i);
// c1[1] daria "A:", c1[2] daria "How are you?", c1[3] daria "B:" e c1[4] daria "I'm fine, thanks."
var c2 = chat2.match(/\b(A:)(.*?)\b/i);
// c2[1] daria "A:", c2[2] daria "How are you?"

console.log(c1);
// Resultado:
Array [ "A:How are you?B:", "A:", "How are you?", "B:", "" ]

console.log(c2);
// Resultado:
Array [ "A:", "A:", "" ]

javascript regex

2 answers

3


You can use in a more simplified way, without the ?, $ or \b:

(A:)(.*)(B:)(.*)

When you use the ? in the last group, you will have to use $ so that it knows the end of the string. Therefore, it becomes unnecessary if you use only .* that will capture the entire string to the end of the line.

var chat1 = "A:How are you?B:I'm fine, thanks.";
var chat2 = "A:How are you?";

var c1 = chat1.match(/(A:)(.*)(B:)(.*)/i);
var c2 = chat2.match(/(A:)(.*)/i);
console.log(c1);
console.log(c2);

  • Is there any way to get the exact expression and nothing else? Ex: if var c1 were chat2.match(/(A:)(.*)/i) would not marry, and vice versa, if var c2were chat1.match(/(A:)(.*)(B:)(.*)/i) nor would you marry.

  • In the original the variables chat1 and chat2 are actually a single variable (var chat), which can contain both values. What happens is that the expression .match(/(A:)(.*)/i), when applied to the variable chat1 also returns true, including B:I’m fine, Thanks. (the answer), undesirable. What I would like is that expression .match(/(A:)(.*)/i) only relate if the expression were only "A:How are you?" (the question) and not "A:How are you? B:I’m fine, Thanks." (the question and the answer).

  • Did not work. The result gives null for both expressions.

  • @Eden If the A: will always end in ? (for always a question), this may help https://jsfiddle.net/o19n8824/2/ (I took the /i, I don’t know if it’s necessary)

  • 1º I need to keep the capture groups the way they are so I can use them individually later; (A:) separate from (.*) and not along the way you put it: (A:.*). 2º I don’t want you to regex her .match(/(A:)(.*)/i) extracts the part of the question, and yes that gives true marry the whole expression (A:How are you?) and false/null if it also contains the part of the reply.

  • @Eden When executing the snippet, see that the array returns the separate values. You can use them by taking the index.

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0

Just add the character $ at the end of the expressions.

var chat1 = "A:How are you?B:I'm fine, thanks.";
var regex = /\b(A:)(.*?)(B:)(.*?)$/i;
var resultado = chat1.match(regex);
console.log(resultado);

var chat2 = "A:How are you?";
var regex = /\b(A:)(.*?)$/i;
var resultado = chat2.match(regex);
console.log(resultado);

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