I need to capitalize the first letter of each line inside a div
In the example below the result should be:

Lorem ipsum
Dolor sit

Amet

So each \n and first letter should be replaced by \n and capital letter

Please help me abut the regex part of my code

$('button').on('click', function(){
  let str = $('#wrap').text();
  let result = str.replace(/\n a-z/, /\n A-Z/); // how to write this?
  $('#wrap').text(result);
});

.wrap{white-space:pre-wrap;}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class='wrap' id='wrap'>
lorem ipsum
dolor sit

amet
</div>
<button>CLICK</button>

CodePudding user response：

You can use \n\s?\p{Ll}.

1. \n ( new line )
2. \s*? ( optional white spaces )
3. \p{Ll} ( any lowercase letter )

And use the replacement function to match the first letter and replace it with its upper case with toUpperCase() function.

$('button').on('click', function(){
  let str = $('#wrap').text();
  let result = str.replace(/\n\s*?\p{Ll}/gu, (v) => v.toUpperCase());
  $('#wrap').text(result);
});

.wrap{white-space:pre-wrap;}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class='wrap' id='wrap'>
čorem ipsum
dolor sit

amet
</div>
<button>CLICK</button>

CodePudding user response：

Consider the following.

$('button').on('click', function() {
  var parts = $(".wrap").text().split("\n");
  $.each(parts, function(i, line) {
    console.log("Line "   i, line);
    parts[i] = line.substr(0, 1).toUpperCase()   line.substr(1);
  });
  $(".wrap").html(parts.join("\r\n"));
});

.wrap {
  white-space: pre-wrap;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class='wrap' id='wrap'>lorem ipsum
dolor sit

amet</div>
<button>CLICK</button>

This assumes that your HTML or Text has End of Line characters (\r\n or just \n).