input只能輸入數字並限制長度

<style>

/*在chrome下移除input[number]的上下箭頭*/

input::-webkit-outer-spin-button,
input::-webkit-inner-spin-button{
    -webkit-appearance: none !important;
    margin: 0;
}
/*在firefox下移除input[number]的上下箭頭*/
input[type="number"]{-moz-appearance:textfield;}

<style>

<input type="number" oninput="if(value.length>5)value=value.slice(0,5)">