How to access an object property value in JavaScript

Jun 10, 2020

Learn the two ways to read an object property value in JavaScript, the dot syntax and the square brackets accessor for dynamic or invalid key names.

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Say you have this object:

const dog = {
  name: 'Roger'
}

To get the value of the name property, you can use the dot syntax, like this:

dog.name

Or you can use the square brackets property accessor syntax:

dog['name']

This is especially useful when a property has not a valid variable name, like the name:

const dog = {
  'the name': 'Roger'
}

dog['the name']

and it’s also very useful when you don’t know the property name beforehand, and you evaluate it programmatically, like in this example that loops through the object property names:

const dog = {
  'the name': 'Roger'
}

for (const [key, value] of Object.entries(dog)) {
  console.log(value)
}

Tagged: JavaScript · All topics

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