Discovering escape characters while iterating through a string in javascript

Question

Discovering escape characters while iterating through a string in javascript

I have a situation where I must rearrange a string into an array for a unique user display. Whenever encountering an escape character (such as \n for a new line), it needs to be added as a separate item in the array.

For example, if the string is:

sampe\nanother sample HERE\n\n\nfinal

It should be formatted as:

["sampe", "another sample HERE", "", "", "final"]

In this case, the empty strings represent the new lines within the array. How can this be accomplished?

UPDATE: There is a special condition where any content enclosed between ${ and } should also be considered as a separate array element.

For instance:

"sampe\n${abc}another sample HERE\n\n\nfinal"

In such a scenario, the array should appear as:

["sampale", "${abc}", "another sample HERE", "", "", "final"]

Therefore, this functionality should also be attainable. Currently, without taking into account the escape characters, I am iterating through the array to identify occurrences of ${ and }. How can this be achieved while considering the \n escape character?

javascript arrays string html-escape-characters

Answer 1

Answer №1

As mentioned by @JaromandaX, you have the option to utilize string.split("\n") for splitting your string into an array.
In case of the ${...} pattern, a possible approach is using string.matchAll(/\$\{.*?\}/g) to identify these sequences within the string (adjust .* if needed), followed by string splitting with Array.prototype.reduce() similar to this:

// Locate and transform all matches into an array
let matches = Array.from(string.matchAll(/\$\{.*?\}/g));

let result = matches.reduce((res, mat) => {
    res.array.push(string.substring(res.last, mat.index), mat[0]); // each match creates 2 additional segments
    res.last = mat.index + mat[0].length; // next segment initiates after the match
    return res;
// Utilize an array to hold the output and an integer to track the start of each segment
}, {array: [], last: 0});

// Append any remaining segment to the result
result.array.push(string.substring(result.last));

// Retain only the segments array as that's the desired outcome
result = result.array;

Answer 2

As mentioned by @JaromandaX, you have the option to utilize string.split("\n") for splitting your string into an array.
In case of the ${...} pattern, a possible approach is using string.matchAll(/\$\{.*?\}/g) to identify these sequences within the string (adjust .* if needed), followed by string splitting with Array.prototype.reduce() similar to this:

// Locate and transform all matches into an array
let matches = Array.from(string.matchAll(/\$\{.*?\}/g));

let result = matches.reduce((res, mat) => {
    res.array.push(string.substring(res.last, mat.index), mat[0]); // each match creates 2 additional segments
    res.last = mat.index + mat[0].length; // next segment initiates after the match
    return res;
// Utilize an array to hold the output and an integer to track the start of each segment
}, {array: [], last: 0});

// Append any remaining segment to the result
result.array.push(string.substring(result.last));

// Retain only the segments array as that's the desired outcome
result = result.array;

Discovering escape characters while iterating through a string in javascript

Answer №1

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