JavaScript: Assignment Operators

Assignment Operators

An assignment operator assigns a value to its left operand based on the value of its right operand. The first operand must be a variable and basic assignment operator is equal (=), which assigns the value of its right operand to its left operand. That is, a = b assigns the value of b to a.

In addition to the regular assignment operator "=" the other assignment operators are shorthand for standard operations, as shown in the following table.

Shorthand Expression Description
a +=b a = a + b Adds 2 numbers and assigns the result to the first.
a -= b a = a - b Subtracts 2 numbers and assigns the result to the first.
a *= b a = a*b Multiplies 2 numbers and assigns the result to the first.
a /=b a = a/b Divides 2 numbers and assigns the result to the first.
a %= b a = a%b Computes the modulus of 2 numbers and assigns the result to the first.
a<<=b a = a<<b Performs a left shift and assigns the result to the first operand.
a>>=b a = a>>b Performs a sign-propagating right shift and assigns the result to the first operand.
a>>>=b a = a>>>b Performs a zero-fill right shift and assigns the result to the first operand.
a&= b a = a&b Performs a bitwise AND and assigns the result to the first operand.
a^= b a = a^b Performs a bitwise XOR and assigns the result to the first operand.
a |=b a = a|b Performs a bitwise OR and assigns the result to the first operand.
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JavaScript: Tips of the Day

arrow function

```const user = {
email: "[email protected]",
updateEmail: email => {
this.email = email
}
}

user.updateEmail("[email protected]")
console.log(user.email)
```

The updateEmail function is an arrow function, and is not bound to the user object. This means that the this keyword is not referring to the user object, but refers to the global scope in this case. The value of email within the user object does not get updated. When logging the value of user.email, the original value of [email protected] gets returned.

Ref: https://bit.ly/2IUFeTa