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2018-10-12 15:37:13 -04:00
---
title: Remove an Item from an Array
---
## Remove an Item from an Array
### Solution
```javascript
const immutableReducer = (state = [0,1,2,3,4,5], action) => {
switch(action.type) {
case 'REMOVE_ITEM':
// don't mutate state here or the tests will fail
return [...state.slice(0, action.index), ...state.slice(action.index + 1, state.length)];
// or return state.slice(0, action.index).concat(state.slice(action.index + 1, state.length));
default:
return state;
}
};
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const removeItem = (index) => {
return {
type: 'REMOVE_ITEM',
index
}
}
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const store = Redux.createStore(immutableReducer);
```
### Notes
* array.slice(fromIndex, untilIndex) returns a new array
* 1st slice from the first item's index (0 inclusive) until indexToRemove(action.index exclusive)
* 2nd slice from item right after indexToRemove (action.index + 1 inclusive) until length (last item's index + 1 exclusive)
* since slice returns a new array, combine both parts with [...array1, ...array2] spread operator
* or combine them with .concat()