CODEWITHSUNDEEP
javascriptif-statementcomparenewlineconditional-statements
aarav
aarav

Reputation: 230

javascript if condition check string with newline symbol i.e \n

In my script I have a string with newline characters. Using newline (\n)character I parsed it to array.

I struggling to compare in my if condition (parsedarray[0]=='newline character'). Please help me to compare the newline character in my if condition. I also tried to alert the parsedarray[0]. It alerts blank alert box.` I am unable to check the newline character in if statement. For instance, I have a single String with multiple newline , tabs consisting of 40 lines. In my script user enter a line number, string for that line number, after receiving both information, I want to replace the newline with entered string in the line number. Here line number is an index. So that again I will construct a single string by joining the parsed string. Also my array size should not grow. or Reduce.??? And importantly I want to validate the given String with the available string, if both matches (other than newline) need to put alert message.

 var strarray=doc.getElementbyid('mytextarea').value;
 var parsedarray=[];
 parsedarray=strarray.split('\\n');`

Upvotes: 2

Views: 30552

Answers (5)

aarav
aarav

Reputation: 230

I recreated the array like adding a delimiter var one=document.forms[0]["mytextarea"].value; myarray=one.split('\|');after each newline character. Then I split the string using the delimiter. Then onwards I can easily accessing the newline \n character by each index. After replacing the string on specific index, again i construct a single string by joining them using same delimiter. var two=myarray.join('|'); Also my alertbox shows now \n, when I tried to print the index. Thanks for all your contribution..

Upvotes: 0

Bharath R
Bharath R

Reputation: 1531

You can do something like this

<html>
<head>
<script>
function myFunction()
{
var strarray=document.getElementById("tre").value;
var eachLine = strarray.split('\\n');
alert('Lines found: ' + eachLine.length);
for(var i = 0, l = eachLine.length; i < l; i++) {
//do add another string to the index here
alert('Line ' + (i+1) + ': ' + eachLine[i]);

}
</script>
</head>
<body>
<textarea id="tre"></textarea>
<button onclick="myFunction()">Click me</button>
</body>
</html>

Upvotes: 0

Guilherme Sehn
Guilherme Sehn

Reputation: 6787

The split method will split your string into an array of strings that were separated by the character you passed as parameter. For example:

var text = 'foo\nbar\nbaz',
    splitted = text.split('\n');

console.log(splitted); // ["foo", "bar", "baz"]

If you want to replace your new line character with another string, you can use the replace method.

var text = 'foo\nbar\nbaz',
    replaced = text.replace(/\n/g, '-');

console.log(replaced); // foo-bar-baz

Upvotes: 0

Joke_Sense10
Joke_Sense10

Reputation: 5402

Instead of split use indexOf to find position of the first occurrence of a specified value in a string.

Eg:

var text="Hello world\n";
if(text.indexOf("\n")==-1){
  alert("No newline characters")
}else{
  alert("Contains newline characters")
}

Upvotes: 11

Daniel Perv&#225;n
Daniel Perv&#225;n

Reputation: 1716

String.split() will not include the delimiter in the resulting array. If you want to find the occurrence of a newline character, I would suggest using String.indexOf("\n") instead.

Upvotes: 1

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