JavaScript Program to Check If a Variable is of Function Type

// program to check if a variable is of function type

function testVariable(variable) {
      
    if(variable instanceof Function) {
        console.log('The variable is of function type');
    }
    else {
        console.log('The variable is not of function type');
    }
}

const count = true;
const x = function() {
    console.log('hello')
};

testVariable(count);
testVariable(x);

Output

The variable is not of function type
The variable is of function type