test if a string is a number javascript code example

Example 1: javascript is variable a string

if (typeof myVar === 'string'){
    //I am indeed a string
}

Example 2: js check if string is integer

function isInt(str) {
  return !isNaN(str) && Number.isInteger(parseFloat(str));
}

Example 3: javascript check if string is number

function isNumeric(num){
  return !isNaN(num)
}
isNumeric("23.33"); //true, checking if string is a number.