我只是做了一个表格，将value变成变量，并试图将它们之间进行比较，但是什么也没发生。
我试图用number（）和parseInt将变量转换为整数，但是没有用。
我试图在函数外部声明变量，但没有用
$('#calculate').click(function(){
var bill = $('#bill').val();
var serveuse = $("#myselect option:selected").val();
var sangs = $('#gars').val();
if(bill===0){
alert('something');
}
else if (bill<10){
alert('somethinge else');
}
else(gars>10 &&bill>20){
alert('something else else');
}
})
我的from中有三个输入，“ sangs”和“ bill”是经典输入类型编号，“ serveuse”是一个选择选项输入。我只想将这三个变量与其他if语句进行比较以输出结果。
答案 0 :(得分：0)
可能import React, { PureComponent } from 'react';
import { Field, reduxForm } from 'redux-form';
import { connect } from 'react-redux';
import { Button } from 'reactstrap';
import axios from 'axios';
import Select from 'react-select';
import { Redirect } from 'react-router-dom';
import PropTypes from 'prop-types';
import EyeIcon from 'mdi-react/EyeIcon';
import Logo from '../../shared/img/logo/logo_light_2.svg';
import * as serverActionTypes from '../../redux/actions/serverActions';
class LogIn extends PureComponent {
static propTypes = {
handleSubmit: PropTypes.func.isRequired,
};
constructor(props) {
super(props);
this.state = {
showPassword: false,
in: false,
};
}
componentDidMount() {
localStorage.clear();
}
.
.
.
.
.
handleEmailChange(event) {
this.setState({ email: event.target.value })
}
handlePasswordChange(event) {
this.setState({password: event.target.value})
handleChange = (selectedOption) => {
console.log("$$$$$$$$$$$$");
console.log(selectedOption.value);
console.log(this.props)
if (selectedOption.value === serverActionTypes.devServer().type) {
console.log("handle dev change");
{this.props.onSelectDevServerAddress}
}
else if (selectedOption.value === serverActionTypes.stageServer().type) {
console.log("handle stage change");
{this.props.onSelectStageServerAddress}
}
else if (selectedOption.value === serverActionTypes.prodServer().type) {
console.log("handle prod change");
{this.props.onSelectProdServerAddress}
}
};
render() {
const { handleSubmit } = this.props;
if (this.state.in === true) {
return <Redirect to={{pathname: "/dashboard"}} />;
}
return (
<div className="account">
<div className="account__wrapper">
<div className="account__card" align="center">
<img
src={Logo}
alt="example-logo"
height="35"
style={{marginBottom: '50px'}}
/>
</div>
<div className="account__card">
<form className="form form--horizontal" onSubmit={handleSubmit}>
<div className="form__form-group">
<span className="form__form-group-label">E-mail</span>
<div className="form__form-group-field">
<Field
name="email"
component="input"
type="email"
placeholder="example@mail.com"
value={this.state.email}
onChange={this.handleEmailChange.bind(this)}
/>
</div>
</div>
<div className="form__form-group">
<span className="form__form-group-label">Password</span>
<div className="form__form-group-field">
<Field
name="password"
component="input"
type={this.state.showPassword ? 'text' : 'password'}
placeholder="Password"
value={this.state.password}
onChange={this.handlePasswordChange.bind(this)}
/>
<button
className={`form__form-group-button${this.state.showPassword ? ' active' : ''}`}
onClick={e => this.showPassword(e)}
><EyeIcon />
</button>
</div>
</div>
<div className="form__form-group">
<span className="form__form-group-label">Server</span>
<div className="form__form-group-field">
<div className="form__form-group-input-wrap">
<Select
name='server_address_selector'
value='prod.example.com'
onChange={this.handleChange}
options={[
{ value: 'dev.example.com', label: 'Dev' },
{ value: 'stage.example.com', label: 'Stage' },
{ value: 'prod.example.com', label: 'Prod' },
]}
clearable={false}
className="form__form-group-select"
/>
</div>
</div>
</div>
<Button
color="success"
onClick={this.onLogin.bind(this)}
outline>
Sign In
</Button>
<Button
color="success"
onClick={this.props.onSelectDevServerAddress}
outline>
DEV
</Button>
<Button
color="success"
onClick={this.props.onSelectStageServerAddress}
outline>
STAGE
</Button>
<Button
color="success"
onClick={this.props.onSelectProdServerAddress}
outline>
PROD
</Button>
</form>
</div>
</div>
</div>
);
}
}
const mapStateToProps = state => {
return {
ipAddress: state.server
}
}
const mapDispatchToProps = dispatch => ({
onSelectDevServerAddress: () => dispatch(serverActionTypes.devServer()),
onSelectStageServerAddress: () => dispatch(serverActionTypes.stageServer()),
onSelectProdServerAddress: () => dispatch(serverActionTypes.prodServer()),
});
LogIn = connect(
mapStateToProps,
mapDispatchToProps
)(LogIn);
export default reduxForm({
form: 'log_in_form'
})(LogIn);
必须是else(gars>10 &&bill>20)
和 gars 必须是 sangs
答案 1 :(得分：0)
$('#bill').val()将为您提供一个字符串结果，例如"0"。
`"0" !== 0`
因此您需要先将其转换为数字，例如
var bill = $('#bill').val() * 1;
或者，使用==会自动转换："0" == 0
其他问题：
var sangs = ...
if (gars > ...
和
if () { } else if () { } else () {}
缺少else
您也有很大一部分缺少结果，因此您可能需要没有else子句的最终if（例如，如果bill == 11，那么您将不会收到警报）