# Error accessing object property in JavaScript

When accessing an object property, the name of that property cannot be stored in a variable. Let's see why. Suppose we have such an object:

`let obj = {a: 1, b: 2, c: 3};`

Let the variable store the name of the property whose value we want to get:

`let key = 'a';`

Let's try to access the object property using this variable:

`console.log(obj.key); // undefined`

The above code will not work because we are actually looking for the property named `'key'`, not the property whose name is stored in the variable `key`. That is, in fact, our code is equivalent to the following:

`console.log(obj['key']);`

The only way to access an element by key from a variable is to write this variable in square brackets:

`console.log(obj[key]);`

Fix the error in the following code:

`let obj = {x: 1, y: 2, z: 3}; let prop = 'x'; console.log(obj.prop);`

Fix the error in the following code:

`let obj = {x: 1, y: 2, z: 3}; let prop = 'x'; console.log(obj['prop']);`
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