Concatenate string in typescript/javascript

Question

EDIT: This string is a part of json and i am writing it onto a file. In that json file i see the escape charaters. With console.log, I don't see any escape character.

I am trying to concatenate a string such that I get the following output:

"OR("1admin", "2admin")"

But the output I keep on getting is

"OR(\"1admin\", \"2admin\")"

Sample code

var str = "OR("
for (let i = 1; i < 3; i++) {
  str += '"' + i + 'admin' + '", ';
}
str = str.trim().substring(0, str.length - 2).concat(')')
console.log(str)

I have tried using regex and string split. eg.

.replace(/'/g, '"') This when i tried something like this "'" + i + "admin" + "', " and tried to replace ' with "

.split('\\').join('').trim() This also didn' work.

What am I doing wrong?

"OR("1admin", "2admin")" is not a syntactically correct string. The second one on the other hand is a string with the character sequence you want: i.e. 'O', 'R', '(', '"', ... . In other words, you already got the right result. The string "\"" is the string consisting of the character '"'. A backlash character '\' is required to escape the '"' character so that it doesn't break string parsing early. — FK82
– FK82, Commented May 29, 2019 at 13:41
See escape notation and Single quotes vs. double quotes | your output is actually correct... — vaku
– vaku, Commented May 29, 2019 at 13:45
@JonasWilms Technically I'm not answering the question. Let's see what OP says. :) — FK82
– FK82, Commented May 29, 2019 at 13:46

FK82 · Accepted Answer · 2019-05-29 17:08:59Z

2

As mentioned, you already got the correct result in your original snippet.

If the character escape syntax seems curious to you, I'd recommend something like the following using template strings.

You can write the " in template strings unescaped and use interpolation to print your variables.

Edit: Seems like you want JSON formatting. You can use JSON.stringify for that. JSON formatted strings will contain escape characters that show up in console.log output.

const f = (n, s) => {
    const a = new Array(n)
      .fill()
      .map((_, i) => `"${i + 1}${s}"`);
    return `OR(${a.join(', ')})`;
}

console.log(`output: ${f(2, "admin")}`)
console.log(`json-formatted: ${JSON.stringify(f(2, "admin"))}`)

edited May 29, 2019 at 17:08

answered May 29, 2019 at 13:58

FK82

5,0754 gold badges34 silver badges44 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Harijs Deksnis · Accepted Answer · 2019-05-29 13:58:58Z

0

This seems to do the job:

const NUM_ADMINS = 2;
const CONCAT_STRING =
 `OR(${
   Array(NUM_ADMINS)
   .fill()
   .map((_, idx) => `"${idx + 1}admin"`)
   .join(", ")})`;

It creates a new array with the needed number of admins, then maps it to strings in th form "admin", joins with a comma and a space. And then it it is all wrapped in a "OR()" string.

edited May 29, 2019 at 13:58

answered May 29, 2019 at 13:52

Harijs Deksnis

1,5061 gold badge14 silver badges24 bronze badges

Comments

Jeremy Thille · Accepted Answer · 2019-05-29 14:17:06Z

0

var str = '"OR("'
var adm = 'admin"'
var end = ')"'
for (let i = 1; i < 3; i++) {
  str += i + adm + ', '
}
str = str.trim().substring(0, str.length - 2)
str += end
console.log(str);

try running this snippet. if the implementation is fyn for you. Result is what you expected.

edited May 29, 2019 at 14:17

Jeremy Thille

26.4k12 gold badges48 silver badges64 bronze badges

answered May 29, 2019 at 14:13

Rosey Khatun

892 silver badges9 bronze badges

Collectives™ on Stack Overflow

Concatenate string in typescript/javascript

3 Answers 3

Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related