Optional arguments in JavaScript functions
JavaScript is extremely broad-minded about the number of arguments you
pass to a function. If you pass too many, the extra ones are ignored. If
you pass too few, the missing parameters get assigned the value
undefined
.
function square(x) {
return x * x
}
console.log(square(4, true, "hedgehog"))
function minus(a, b) {
if (b === undefined) return -a
else return a - b
}
console.log(minus(10))
console.log(minus(10, 5))
Function parameters can also be given default values
function power(base, exponent = 2) {
let result = 1
for (let count = 0; count < exponent; count++) {
result *= base
}
return result
}
console.log(power(4))
console.log(power(2, 6))