我想在提交之前制定一個邏輯，其中指出輸入值不應為任何空值且應大于 0。
const minValue = (input) => {
if(input < 0){
alert('input has to be greater than 0')
}else{
return input;
}
}
<Form className = "workout-form">
<div className ="form-row">
<label className ="form__label">Distance</label>
<input type = 'number' value = {distance} min = '0' onChange = {(e) => setDistance(minValue(e.target.value))} className ="form__input form__input--distance" placeholder="mi" autoFocus required/>
</div>
<button className ="form-btn" onClick = {submitWorkout}>Add Workout</button>
</Form>
uj5u.com熱心網友回復：
如果此代碼用于檢查負值，您應該能夠將 if (input < 0) 更改為 if ((input < 0) || (input != ""))
uj5u.com熱心網友回復：
const handleChange = e => {
const value = parseInt(e.target.value);
if(!isNaN(value) && value > 1){
setDistance(value)
}
}onChange={handleChange}轉載請註明出處，本文鏈接：https://www.uj5u.com/gongcheng/375024.html
標籤：javascript 形式 验证 输入 表单提交
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