从数字开头仅删除不必要的0

Question

我有一个代表数字的js字符串。我想从字符串的开头仅删除不必要的0，如果不存在数字，则用正则表达式在逗号前放置0：

<div class="container-fluid">
        <div class="row">
            <div class="col-md-12">
                @if(Session::has('message'))
                    <div class="alert">
                        <div class="alert alert-success">
                            <strong>{{ Session::get('message') }}</strong>
                        </div>
                    </div>
                @endif
                @if ($errors->any())
                    {{ implode('', $errors->all('<div>:message</div>')) }}
                @endif
                {!! Form::open([
                    'route' => 'submitTestForm'
                ]) !!}
                    <ul class="nav nav-pills mb-3" id="pills-tab" role="tablist">
                        <li class="nav-item @if($errors->has('name') === true && $errors->has('email') === false || $errors->has('name') === true && $errors->has('email') === true) active @endif">
                            <a class="nav-link  @if($errors->has('name') === true && $errors->has('email') === false || $errors->has('name') === true && $errors->has('email') === true || $errors->has('name') === false && $errors->has('email') === false) active @endif" id="pills-formOne-tab" data-toggle="pill" href="#pills-formOne" role="tab" aria-controls="pills-home" aria-selected="true">Form One</a>
                        </li>
                        <li class="nav-item  @if($errors->has('name') === false && $errors->has('email') === true) active @endif">
                            <a class="nav-link @if($errors->has('name') === false && $errors->has('email') === true) active @else disabled @endif" id="pills-formTwo-tab" data-toggle="pill" href="#pills-formTwo" role="tab" aria-controls="pills-profile" aria-selected="false">Form Two</a>
                        </li>
                    </ul>
                    <div class="tab-content" id="pills-tabContent">
                        <div class="tab-pane fade @if($errors->has('name') === true && $errors->has('email') === false || $errors->has('name') === true && $errors->has('email') === true) show active in @elseif($errors->has('name') === false && $errors->has('email') === false) show in active @endif" id="pills-formOne" role="tabpanel" aria-labelledby="pills-formOne-tab">
                           <div class="form-group">
                               <input type="text" name="name" value="{{ old('name') }}" placeholder="Enter Name">
                           </div>
                        </div>

                        <div class="tab-pane fade @if($errors->has('name') === false && $errors->has('email') === true) show active in @endif" id="pills-formTwo" role="tabpanel" aria-labelledby="pills-formTwo-tab">
                            <div class="form-group">
                                <input type="email" name="email" value="{{ old('email') }}" placeholder="Enter Email">
                            </div>
                        </div>
                    </div>
                    <hr>
                    <div class="form-control">
                        <button class="btn btn-sm btn-success">Submit</button>
                    </div>
                {!! Form::close() !!}
            </div>
        </div>
    </div>

我尝试过：

var regex = ?
var replace = ?

new = "0001,3".replace(regex, replace); // 1,3
new = ",3".replace(regex, replace); // 0,3
new = "000,34".replace(regex, replace); // 0,34
new = "0201,3".replace(regex, replace); // 201,3
new = "0002,03".replace(regex, replace); // 2,03

但是看起来第二次替换不起作用。

Answer 1

使用正则表达式替换0。

function trim(txt) {
  return txt.replace(/^(0*)(,?)/, (full, zeros, end) => end ? "0," : "");
  // If the zeros are directly followed by a `,` then keep a `0`
  // use `function (){return arguments[2] ? "0," : "";}` for ES5
}

console.log(trim("0001,3"));
console.log(trim(",3"));
console.log(trim("000,34"));
console.log(trim("0201,3"));
console.log(trim("0002,03"));

使用解析和字符串化（将在开头和结尾处替换0）

function trim(txt) {
  return String(+(txt.replace(",", "."))).replace(".", ",");
}

console.log(trim("0001,3"));
console.log(trim(",3"));
console.log(trim("000,34"));
console.log(trim("0201,3"));
console.log(trim("0002,03"));

Answer 2

function trimZeroesLeft(txt) {
  return ("0" + txt).replace(/^0+(?=\d)/g, "");
}

function trimZeroesRight(txt) {
  return txt.replace(/,0*$|(,\d+?)0+$/g, "$1");
}

function trimZeroes(txt) {
  return ("0"+txt).replace(/^0+(?=\d)|,0*$|(,\d+?)0+$/g, "$1");
}


let arr = ["0001,3", ",300", "000,34", "0201,30", "0002,03", "012,0", "0,00"];

console.log("trimZeroesLeft", arr.map(v => `${v} -> ${trimZeroesLeft(v)}`));
console.log("trimZeroesRight", arr.map(v => `${v} -> ${trimZeroesRight(v)}`));
console.log("trimZeroes", arr.map(v => `${v} -> ${trimZeroes(v)}`));

.as-console-wrapper{top:0;max-height:100%!important}