问题
How can I dynamically set the name of the array in state, to get it from state.
onCheckBoxItemClickList(e, value, path) {
console.log(e.target.checked)
if (e.target.checked) {
//append to array
this.setState({
[path]: this.state.[path].concat([value])
})
} else {
//remove from array
this.setState({
[path]: this.state.[path].filter(function (val) {
return val !== value
})
})
}
}
I know how to dynamically set and get a key in state, but when I try and do
[path]: this.state.[path].concat([value])
I get the below error:
Any help would be greatly appreciated, Thanks
回答1:
You have an extra dot in your code (after state):
[path]: this.state.[path].concat([value])
Should be:
[path]: this.state[path].concat([value])
Then whenever you want to set the state based on the previous state, you should use the setState
which takes a callback in, with the prevState
as argument.
So your code should look something like:
onCheckBoxItemClickList(e, value, path) {
console.log(e.target.checked)
if (e.target.checked) {
//append to array
this.setState(prevState => ({
[path]: prevState[path].concat([value])
}))
} else {
//remove from array
this.setState(prevState => ({
[path]: prevState[path].filter(function (val) {
return val !== value
})
}))
}
}
来源:https://stackoverflow.com/questions/54129355/how-to-dynamically-get-state-array-name-react