words is only replaced one time

Question

here is my code

</script>
  function myFunction() {
   var a = ["a.m.","p.m","u.k."];
   var b = ["its_morning","its_noon","unKnown_thing"];
   var str = document.getElementById("textBox1").value;
      for (var k = 0; k < a.length; k++) {
        str = str.replace(a[k], b[k]); 
                                         };
   document.getElementById('textBox2').value = str;
     }
</script>

<body>

  <textarea onkeyup="myFunction();"id="textBox1"></textarea>
  <TEXTAREA type="text" id="textBox2"></TEXTAREA>
</body>

when i type 'a.m.' its working fine but when i type it again its not changing . like:

'a.m. hello world a.m.'

gives results

'its_morning hello world a.m.'

here the last 'a.m.' must be replaced but i dont know wats wrong with it

please answer in javascript ,im not familiar with jquery.

i dont know why but nothing is printing in textbox2 while using this `escapeRegExp` thing — Nakul, Oct 18 '14 at 16:55

edi9999 · Answer 1 · 2014-10-18T16:41:33.437

2

The problem is that the replace will not replaceAll automatically. You have to use global regex for this.

eg instead of writing

string.replace("search","replace")

write:

string.replace(/search/g,"replace")

The /g flags means searching globally, eg replaceAll

In your case, I would write the a array as an array of regexes instead:

var a = [ /a\.m\./g, /p\.m/g, /u\.k\./g ];

However, you need to escape special characters, like .

Your code should than be:

<script>
  function myFunction() {
   var a = [
      /a\.m\./g,
      /p\.m/g,
      /u\.k\./g
   ];
   var b = ["its_morning","its_noon","unKnown_thing"];
   var str = document.getElementById("textBox1").value;
      for (var k = 0; k < a.length; k++) {
        str = str.replace(a[k], b[k]); 
                                         };
   document.getElementById('textBox2').value = str;
     }
</script>

edited Oct 18 '14 at 16:41

answered Oct 18 '14 at 16:21

edi9999

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hey @edi9999 can i use string.replace(a[k]/g,b[k]); – Nakul Oct 18 '14 at 16:30
That wouldn't work, JS would think that you're tring to divide a[k] by g. Why are you asking this ? – edi9999 Oct 18 '14 at 16:31
because im working with arrays – Nakul Oct 18 '14 at 16:32
You can write it like this : `var a = [/a\.m\./g,/p\.m/g,/u\.k\./g];` – edi9999 Oct 18 '14 at 16:33
are you replaceing these [] brackets with these weird chars – Nakul Oct 18 '14 at 16:35
/test/g is a shorthand for writing new RegExp("test",g) – edi9999 Oct 18 '14 at 16:36
please edit my question code so i can understand it easy way, – Nakul Oct 18 '14 at 16:39
Done. Hope that helps – edi9999 Oct 18 '14 at 16:41
thanks edi , but what if i want to add more words in my array'a' sorry its taking too long but please help me to do this – Nakul Oct 18 '14 at 16:43
You will need to write /string/g instead of "string", and add a "\" before any of the following characters: `.?*+^$\(){}|-` – edi9999 Oct 18 '14 at 16:47

Amit Joki · Accepted Answer · 2014-10-18T16:29:14.353

-2

String.replace(String, String) just replaces the first occurence.

You can use the regex with "g" modifier so it replaces every occurence. Since, it is dynamic string, you should use RegExp constructor.

str = str.replace(new RegExp(a[k].replace(/\./g, '\\.'),"g"), b[k]);

edited Oct 18 '14 at 16:29

answered Oct 18 '14 at 16:21

Amit Joki

58,320
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1

The problem with this is that it will match "aim", because of the `.` or any character in the middle – edi9999 Oct 18 '14 at 16:23
i tried this one it has two problems one is : the case insensetive proble and the second is : it takes 'a.m.' and 'akmk' as same thing. – Nakul Oct 18 '14 at 16:24
1

@Nakul case-insensitive is not applied, so it is not a problem – Amit Joki Oct 18 '14 at 16:26
@AmitJoki i tried this and i want case sensitive replacement . – Nakul Oct 18 '14 at 16:33
Downvotes? Really after the edit?? Great! – Amit Joki Oct 18 '14 at 16:53
@AmitJoki i think your way is more sufficient way to do this thing. – Nakul Oct 18 '14 at 17:12

words is only replaced one time

2 Answers2