I have an empty object and want to create an object inside object dynamically.
const obj = {}
obj["test1"]["test1.1"] = x //initialize to some variable
I get the error
Uncaught TypeError: Cannot set property 'test1.1' of undefined
I want the output to be like
obj = {
test1: {
test1.1: x //some variable
}
}
By dynamically if you mean the name of the attribute is not certain, you can use brackets to insert dynamic variable names:
const arg1 = 'test1';
const arg2 = 'test1.1';
const x = 42;
// assign both variable names dynamically
const obj = { [arg1]: { [arg2]: x } };
console.log(obj);
You can do this in two steps or one
const x = "some var";
const obj = {};
obj["test1"] = {
"test1.1": x
}; // assign the nested object
console.log(obj);
// or
const y = "some var";
const obj1 = { // assign the complete object
test1: {
"test1.1": x
}
};
console.log(obj1);You need to initialize obj["test1"] = {}
const obj = {}
obj["test1"] = {}
obj["test1"]["test1.1"] = 'x'
console.log(obj)var obj = {}
_.set(obj, ["test1", "test1.1"], 'x');
console.log(obj)<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.20/lodash.min.js"></script>
A more functional approach
const arr = {};
// respecting immutability
const rewroteArray = {...arr, da: {"foo": 2}}
console.log(rewroteArray);As creating an Object with this syntax const obj = {} is equal const obj = new Object(). You can use the second method to define any level deep of properties definition.
const obj = new Object({
"test1": {
"test-1":'x'
}
});
console.log(obj);
new Object() at all
obj['test1'] = { 'test1.1': x }const obj = { test1: { "test1.1": x } }? Then you make the declaration, assignment, and full object creation all at once.