• C++

using namespace std;
string s;
int x {n}, y, c;
do {
    y = x % b;
    c = y > 9 ? 'a' - 10 : '0';
    s = char(c + y) + s;
} while (x /= b);

• Go

s := strconv.FormatInt(int64(n), b)

• JS

let s = n.toString(b);

• Java

String s = Integer.toString(n, b);

• Pascal

function IntToBaseStr(n: longword; const b: cardinal): string;
const
  digits = '0123456789abcdefghijklmnopqrstuvwxyz';
var
  remainder: longword;
begin
  Result := '';
  repeat
    DivMod(n, b, n, remainder);
    result := digits[remainder + 1] + result;
  until n = 0;
end;

• Pascal

s := IntToStrBase(n,b);

• Perl

sub int_to_base_str {
    my ($n, $b) = @_;
    my $digits = '0123456789abcdefghijklmnopqrstuvwxyz';
    my ($s, $q, $remainder) = ('');

    return '0' if $n == 0;

    use integer;

    while ($n) {
        ($n, $remainder) = ($n / $b, $n % $b), 
        $s = substr($digits, $remainder, 1) . $s;
    }

    return $s
}

• Python

def parse(value, base):
    array = digits + ascii_lowercase
    def f(value):
        if value < base:
            return array[value]
        n, index = divmod(value, base)
        return f(n) + array[index]
    return f(value)
s = parse(n, b)

• Python

def int_to_base_str(n, b):
    digits = '0123456789abcdefghijklmnopqrstuvwxyz'
    s = ''
    if n == 0: return '0'
    while n:
        n, remainder = divmod(n, b)
        s = digits[remainder] + s
    return s

• Python

s = numpy.base_repr(n, b)

• Python

array = digits + ascii_lowercase
def f(value):
    if value < b:
        return array[value]
    value, index = divmod(value, b)
    return f(value) + array[index]
s = f(n)

• Ruby

s = n.to_s(b)

• Rust

let s = radix(n, b);