Since JavaScript is a dynamically typed language, its variables can contain data of any type.
Therefore, we need a way to check for the data type of a variable.
In this article, we’ll look at ways to check if the data type of a JavaScript variable is a boolean.
One way to check if a variable is a boolean variable is using the typeof
operator.
To do this, we write:
if (typeof variable === "boolean") {
// ...
}
We check if the data of the variable
variable is a boolean with the expression if the if
statement.
It’ll return true
if variable
is a boolean.
Another way to check is a variable is a boolean is to check if it equals to true
or false
with the ===
operator.
For instance, we can write:
const isBoolean = (val) => {
return val === false || val === true;
}
console.log(isBoolean(true))
console.log(isBoolean('abc'))
We create the isBoolean
that checks whether val
is false
or true
.
Since we use the ===
operator, either expression in the OR expression will return true
only if val
is exactly equal to the value being compared.
Therefore, the first console log should log true
.
And the 2nd one should log false
.
#programming #javascript #technology