when i use event.target.value in <ul><li></li>...</ul>
in react ,i cannot get correct value.
import React from 'react';
class NewComponent extends React.Component {
constructor(props) {
super(props);
this.state = {};
}
click = (event) => {
console.log(event.target.value);
};
render() {
return (
<li value="a" onClick={this.click}>A</li>
);
}
}
export default NewComponent;
value is 0
but
click = (event) => {
console.log(event.target.value);
};
render() {
return (
<li value="1" onClick={this.click}>A</li>
);
}
value is 1
I don't know why I put string in li's value, it cannot get correct,but if i put number in li's value, it can get correct
Reading your example, and interpreting it a bit, I think that what you're trying to do is:
Have som value displayed inside a list element.
Use that same value for something when the list element is clicked on.
I think the solution you're looking for then is passing that value directly to the function handling the onClick:
import React from 'react';
class NewComponent extends React.Component {
click = (value) => {
console.log(value);
};
render() {
const myValue = "a";
return (
<li onClick={ ()=> this.click(myValue) }>{myValue}</li>
);
}
}
export default NewComponent;
You can also use an array of objects and a map function for having the same effect with a list of values, while differentiating between the display value and the value you've passed in, as in your example:
import React from 'react';
class NewComponent extends React.Component {
click = (value) => {
console.log(value);
};
render() {
const myValues = [
{display: "A", value: "a"},
{display: "B", value: "b"},
{display: "C", value: "c"}
];
return (
<ul>
{myValues.map(
(value, i) => (<li onClick={ ()=> this.click(value) } key={i} >{value.display}</li>)
)}
</ul>
);
}
}
export default NewComponent;
Li tag value only takes integer argument and e.target.value will override your string value to a numerical value.
It is said clearly in the Li tag's docs, link is attached below. https://developer.mozilla.org/en-US/docs/Web/HTML/Element/li
You have to pass event to the function
click = (event) => {
console.log(event.target.value);
};
render() {
return (
<button value="a" onClick={event => this.click(event)}>A</button>
);
}
It might not be the best way of doing it (using data
attribute) but the code bellow should work. there is also a thorough explanation on why value
doesn't work for <li />
here: How to get value from <li> tag
click = (event) => {
console.log(event.currentTarget.dataset.id);
};
render() {
return (
<li data-id="1" onClick={this.click}>A</li>
);
}
This is not standardized. The value attribute should only be used for input elements and textarea elements and custom components.
You should use a custom component to do this.
const Li = (props) => <li onClick={()=>props.onClick(props.value)}>A</li>
class App extends React.Component {
constructor(props) {
super(props);
this.state = {};
}
click = (value) => {
console.log(value);
};
render() {
return (
<Li value="a" onClick={this.click}>A</Li>
);
}
}
The technical post webpages of this site follow the CC BY-SA 4.0 protocol. If you need to reprint, please indicate the site URL or the original address.Any question please contact:yoyou2525@163.com.