Implements the function
String padStart(String string,int minLength,char padChar)Returns a string,of length at least minLength,consisting of string prepended with as many copies ofpadChar as are necessary to reach that length.For example,
padStart('7',3,'0') returns "007"or padStart('2010',3,'0') returns "2010"
Parameters:
1.string
the string which should appear at the end of the result2.minLength the minimum length the resulting string must have.Can be zero or negative,in which case the input string is always returned.
3.padChar the character to insert at the beginning of the result until the minimum length is reached
Returns:the padded string