js check if is a number code example
Example 1: javascript check if number
//Updated dec 2020
// The first 2 Variations return a Boolean
// They just work the opposite way around
// IsInteger
if (Number.isInteger(val)) {
// It is indeed a number
}
// isNaN (is not a number)
if (isNaN(val)) {
// It is not a number
}
// Another option is typeof which return a string
if (typeof(val) === 'number') {
// Guess what, it's a bloody number!
}
Example 2: javascript check if number
// The first 2 Variations return a Boolean
// They just work the opposite way around
// IsInteger
if (Number.isInteger(val)) {
// It is indeed a number
}
// isNaN (is not a number)
if (isNaN(val)) {
// It is not a number
}
// Another option is typeof which return a string
if (typeof(val) === 'number') {
// Guess what, it's a bloody number!
}
Example 3: javascript is variable a string
if (typeof myVar === 'string'){
//I am indeed a string
}
Example 4: javascript check if variable is number
function isNumber(n) {
return !isNaN(parseFloat(n)) && !isNaN(n - 0);
}