js正則表達式限定輸入框內容爲非負數

 <input type="text" oninput="value=value.replace(/[^\d.]/g,'').replace(/^\.*/,'').replace(/(?<=(\.).*)\1/g, '').replace(/(^0+)(\d)(\.?)/g,'$2$3')">

value.replace(/[^\d.]/g,'')//去除非數字和小數點 eg：'AB..000b.2b.2..24.c'--->'..000.2.2..24.'
.replace(/^\.*/,'')//去除開頭的小數點 eg: '..000.2.2..24.'--->'000.2.2..24'
.replace(/(?<=(\.).*)\1/g, '')//只保留一個小數點 eg：'000.2.2..24'--->'000.2224'
.replace(/(^0+)(\d)(\.?)/g,'$2$3')//去除前面多餘的0 eg：'000.2224'--->'0.2224'