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Match the number of characters between quotes with Javascript?

Suppose my data is as follows

Hello { "I have {g{t{" braces { between "{" { quotes{  "{{"

How can I match a {character that is only between quotes? I am trying to extract the number of occurrences of a specified character only between quotes. Any ideas? The sample must match 6 figures

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2 answers 


var nb = str.split('"').filter(function(_,i){return i%2}).join('')
     .split('{').length - 1;


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Where s

is your string

s.match(/"(.+?)"/g).reduce(function(p,c) {return p + (c.match(/{/g)||[]).length;}, 0);


Since some people find regexes intimidating, I thought it might help step by step how it works. :)

  • The first regex /"(.+?)"/g

    gives you an array of all quoted strings in the original string.
    • Beginning and trailing /

      and /

      refer to regular expressions, as quotation marks refer to strings. g

      rules out that this is a global search - we want all quoted strings, not just the first one.
    • "

      represents the quotation mark before and after the string to be matched
    • .

      means any character
    • +?

      is an idiom that means everything up to the next character in a regular expression; in other words, not a greedy match. If we used *

      instead here +?

      , we could only find one big quoted string between the very first and the very last "

      , with everything else "

      contained in it!
    • We then put in parentheses what we want the match function to actually return to us. In this case, everything is inside the quotation marks, leaving the quotation marks.
  • The second regex will /{/g

    count your characters {

    . By using ||[]

    , we ensure that we get the return value 0

    even if no parentheses were found.
  • The easiest way to sum them up without having to use a loop is to use reduce

    which we are passing the initial value 0

    .
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