javascript type string check code example

Example 1: is string javascript

function isString(value) {
	return typeof value === 'string' || value instanceof String;
}

isString(''); // true
isString(1); // false
isString({}); // false
isString([]); // false
isString(new String('teste')) // true

Example 2: js typeof number

console.log(typeof 93);
// Output = "number"

console.log(typeof 'Maximum');
// Output = 'string'

console.log(typeof false);
// Output = "boolean"

console.log(typeof anUndeclaredVariable);
// Output = "undefined"