if string has number javascript code example
Example 1: javascript check if string is number
// native returns true if the variable does NOT contain a valid number
isNaN(num)
// can be wrapped for making simple and readable
function isNumeric(num){
return !isNaN(num)
}
isNumeric(123) // true
isNumeric('123') // true
isNumeric('1e10000') // true (This translates to Infinity, which is a number)
isNumeric('foo') // false
isNumeric('10px') // false
Example 2: how to check if a string contains numbers in javascript
/**
* Function to check if a string contains numbers
* @author Okoro Redemption
* @param {String} str - The string to be checked.
* @returns {Boolean} str - The result of the check.
*/
function hasNumbers(str){
var regexp = /d/g;
return regexp.test(str);
};
// use function below
hasNumbers("I am 20years old"); // => true
hasNumbers("I am a boy"); // => false