How to reverse a word with javascript

Question

I'd like to reverse a word in a string with javascript, I wrote this code but it isn't working and I can't figure it out why. I want to write a word in a box and when I press the button has to appear the same word but reversed. For example, If I write "hello" in the textbox then it has to appear "olleh".

HTML:

<!DOCTYPE html> 
<html lang="it"> 
<head> 
<meta charset="utf-8"> 
<title>Reverse</title>
</head> 
<body> 
<input type="text" id="primo"><br>
<button type="button" onclick="rev()"> Reverse </button> 
<script type="text/javascript"> 
function rev(){
var string = document.getElementById("primo");
ciao = string.reverse();
document.write(ciao);
}
</script>
</body>

You're outputting the string `"ciao"` - when you want the variable. `document.write(ciao);` — tymeJV, Apr 17 '17 at 17:51
Please do a web search ... there is no built in method for reversing strings but there are solutions all over the web — charlietfl, Apr 17 '17 at 17:52
http://stackoverflow.com/questions/958908/how-do-you-reverse-a-string-in-place-in-javascript — GSazheniuk, Apr 17 '17 at 17:52
@GSazheniuk can you make an answer with my code please, I can't understand how to do it — Gianni, Apr 17 '17 at 17:54
@Gianni as it is stated in first answer, you should first split your string into characters' array, reverse array, and finally join it back to the string: ciao = string.split("").reverse().join(""); — GSazheniuk, Apr 17 '17 at 17:57

score -1 · Accepted Answer · answered Apr 17 '17 at 17:56

String.prototype.reverse = function() {
  return this.split('').reverse().join('');
};

function rev() {
  var field = document.getElementById('primo');
  var ciao = field.value.reverse();
  document.body.insertAdjacentText('beforeend', ciao);
}

<input type="text" id="primo"><br>
<button type="button" onclick="rev()">Reverse</button>

How to reverse a word with javascript

1 Answers1