Reputation: 131
I'm new to React, I try to create add a new element to DOM when onClick. So I play with the state. Like below:
const [number, setNumber] = useState(1);
const [item, setItem] = useState(() => [{id: number,task: `Task ${number}`}]);
const increaseItem = () => {
setNumber(number + 1)
console.log(number)
setItem([...item, {id: number, task: `Task ${number}`}])
console.log(item)
}
But I got an issue when I push the array in useState, the first element of the array copied twice. Here the result of the array:
4 //result of the number
/* Result of item */
0: {id: 1, task: "Task 1"}
1: {id: 1, task: "Task 1"}
2: {id: 2, task: "Task 2"}
3: {id: 3, task: "Task 3"}
Could you show me how the correct way to solve this. Thank you.
Upvotes: 0
Views: 335
Reputation: 173
const [number, setNumber] = useState(1);
const [item, setItem] = useState([{
id: number,
task: `Task ${number}`
}]);
const increaseItem = () => {
const newNumber = number + 1;
setNumber(newNumber);
console.log(number)
setItem([...item, {
id: newNumber,
task: "Task " + newNumber
}]);
console.log(item)
}
increaseItem();
Upvotes: 1