Remove a property in an object immutably
Just use ES6 object destructuring feature
const state = {
c: {
x: '42',
y: '43'
},
}
const { c: { y, ...c } } = state // generates a new 'c' without 'y'
console.log({...state, c }) // put the new c on a new stateYou can use _.omit(object, [paths]) from lodash library
path can be nested for example: _.omit(object, ['key1.key2.key3'])
How about using destructuring assignment syntax?
const original = {
foo: 'bar',
stack: 'overflow',
};
// If the name of the property to remove is constant
const { stack, ...withoutFirst } = original;
console.log(withoutFirst); // Will be { "foo": "bar" }
// If the name of the property to remove is from a variable
const key = 'stack'
const { [key]: value, ...withoutSecond } = original;
console.log(withoutSecond); // Will be { "foo": "bar" }
// To do a deep removal with property names from variables
const deep = {
foo: 'bar',
c: {
x: 1,
y: 2
}
};
const parentKey = 'c';
const childKey = 'y';
// Remove the 'c' element from original
const { [parentKey]: parentValue, ...noChild } = deep;
// Remove the 'y' from the 'c' element
const { [childKey]: removedValue, ...childWithout } = parentValue;
// Merge back together
const withoutThird = { ...noChild, [parentKey]: childWithout };
console.log(withoutThird); // Will be { "foo": "bar", "c": { "x": 1 } }I find ES5 array methods like filter, map and reduce useful because they always return new arrays or objects. In this case I'd use Object.keys to iterate over the object, and Array#reduce to turn it back into an object.
return Object.assign({}, state, {
c: Object.keys(state.c).reduce((result, key) => {
if (key !== 'y') {
result[key] = state.c[key];
}
return result;
}, {})
});