Salesforce JavaScript Developer Practice Exam

What does the unary plus operator do in JavaScript?

1. It converts a variable to a string

2. It converts an operand to a number

3. It creates a new variable

4. It performs addition

The correct answer is: It converts an operand to a number

The unary plus operator in JavaScript serves the primary function of converting its operand into a number. When placed before a variable or value, it attempts to coerce that value into a numeric form. This is particularly useful in scenarios where the operand is a string representation of a number or a value that can be converted to a number, such as a boolean. For example, if you apply the unary plus to the string "42", it will convert it into the number 42. Similarly, applying it to a boolean value like `true` yields the number 1, while `false` results in 0. The unary plus operator is a succinct way to ensure that a value is treated as a number, functioning differently from other operations. It does not create a new variable nor does it perform addition; rather, it simply transforms the existing value. Hence, the correct understanding of the unary plus operator lies in its capability to convert an operand to a number, making it a handy tool in type coercion within JavaScript.