Prepend text to beginning of string

Question

What is the fastest method  to add a new value at the beginning of a string

User · Accepted Answer

var mystr    Doe   mystr    John     mystr    Wouldn t this work for you

User · Answer

You could do it this way      x000D   x000D  var mystr    is my name    x000D  mystr   mystr replace       John     x000D   x000D  console log mystr   x000D   x000D   x000D    disclaimer  http   xkcd com 208

User · Answer

EcmaScript 2017 added special functions to string prototype for that  padStart and padEnd are two new methods available in JavaScript string prototype object  As their name implies  they allow for formatting a string by adding padding characters at the start or the end   Not supported by IE11 and lower  var mystr    quot Doe quot   mystr   mystr padStart  John

User · Answer

you could also do it this way     concat  x   y

User · Answer

Another option would be to use join  var mystr    Matayoshi   mystr     Mariano   mystr  join

User · Answer

If you want to use the version of Javascript called ES 2015  aka ES6  or later  you can use template strings introduced by ES 2015 and recommended by some guidelines  like Airbnb s style guide    const after    test   const mystr    This is    after

User · Answer

You can use  var mystr    Doe   mystr    John     mystr  console log mystr

User · Answer

Since the question is about what is the fastest method  I thought I d throw up add some perf metrics     TL DR The winner  by a wide margin  is the   operator  and please never use regex  https   jsperf com prepend-text-to-string 1

User · Answer

ES6   let after    something after   let text    before text   after

[javascript] Prepend text to beginning of string

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