Answers for "node js if string not a digit"

javascript check if string is number

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

js check if string is number

isNaN(num)         // returns true if the variable does NOT contain a valid number

isNaN(123)         // false
isNaN('123')       // false
isNaN('1e10000')   // false (This translates to Infinity, which is a number)
isNaN('foo')       // true
isNaN('10px')      // true