Retrieving the first digit of a number [duplicate]

Answer 1

    int number = 534;
    int firstDigit = Integer.parseInt(Integer.toString(number).substring(0, 1));

Answer 2

Integer.parseInt will take a string and return a int.

Answer 3

This example works for any double, not just positive integers and takes into account negative numbers or those less than one. For example, 0.000053 would return 5.

private static int getMostSignificantDigit(double value) {
    value = Math.abs(value);
    if (value == 0) return 0;
    while (value < 1) value *= 10;
    char firstChar = String.valueOf(value).charAt(0);
    return Integer.parseInt(firstChar + "");
}

To get the first digit, this sticks with String manipulation as it is far easier to read.

Answer 4

int number = 534;
int firstDigit = number/100; 

( / ) operator in java divide the numbers without considering the reminder so when we divide 534 by 100 , it gives us (5) .

but if you want to get the last number , you can use (%) operator

    int lastDigit = number%10; 

which gives us the reminder of the division , so 534%10 , will yield the number 4 .

Answer 5

int number = 534;
String numberString = "" + number;
char firstLetterchar = numberString.charAt(0);
int firstDigit = Integer.parseInt("" + firstLetterChar);

Answer 6

int firstDigit = Integer.parseInt(Character.toString(firstLetterChar));