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Safely setting object properties with dot notation strings in JavaScript
You can use lodash's set method to set properties at any level safely. Setting first-level properties are pretty straightforward. Nested property access is tricky and you should use a tested library like lodash for it.
You can set a deeply nested object in the following way −
Example
let _ = require("lodash");
let obj = {
a: {
b: {
foo: "test"
},
c: 2
}
};
_.set(obj, "a.b.foo", "test1");
_.set(obj, "a.c", { test2: "bar" });
console.log(obj);Output
This will give the output −
{ a: { b: { foo: 'test1' }, c: { test2: 'bar' } } }You can also write your own setUpdateProp function in the following way −
const setUpdateProp = (object, path, value) => {
if (path.length === 1) object[path[0]] = value;
else if (path.length === 0) throw error;
else {
if (object[path[0]])
return setUpdateProp(object[path[0]], path.slice(1), value);
else {
object[path[0]] = {};
return setUpdateProp(object[path[0]], path.slice(1), value);
}
}
};You can use it by passing an array to access the props.
Example
var obj = {
level1:{
level2:{
level3:{
name: "Foo"
}
},
anotherLevel2: "bar"
}
};
setUpdateProp(obj, ["level1", "level2"], "FooBar");
console.log(obj);Output
This will give the output −
{ level1: { level2: 'FooBar', anotherLevel2: 'bar' } }
Updated on: 27-Nov-2019
563 Views
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