Javascript join array with brackets-CodePudding

In javascript I need to join an array into a string with brackets. For example ['abc', 'yte', 'juu'] => (abc)(yte)(juu). I need the fastest and cleanest way to do this. I tried using the array join operator but it doesnt work on the first and last element.

CodePudding user response：

You can do it with template literals. Use join() with )( separator, and wrap the result with ():

const data = ['abc', 'yte', 'juu'];

const result = `(${data.join(')(')})`;
console.log(result);

CodePudding user response：

Thinking "I need the fastest and cleanest way to do this." is often not ideal. In most cases what people want is the most readable and understandable way to implement a solution.

I quite like the following. Where we first bracket each item in the array with map and then join the items with no delimiter:

const data = ['abc', 'yte', 'juu'];
let brackets = data.map(x => "("   x   ")");
let result = brackets.join("")
console.log(result);

That of course takes two passes over the array. If you really must have the fastest solution just use a for loop:

const data = ['abc', 'yte', 'juu'];
let result = "";
for (let item of data) {
    result  = "("   item   ")";
}
console.log(result);

CodePudding user response：

const list = ['abc', 'yte', 'juu'];
const result = list.map(value => `(${value})`).join("");
console.log(result);

CodePudding user response：

In order to reduce an array to a single value (be that an object, array, string, number, ...) Javascript has the Array.prototype.reduce method, which achieves the desired result in a single loop and line:

console.log(['abc', 'yte', 'juu'].reduce((a,v)=>`${a}(${v})`,''))