## JavaScript & Python

### Details

**Name Kata:** Sum of Digits / Digital Root

**6kuy**

**Description:** Given n, take the sum of the digits of n. If that value has more than one digit, continue reducing in this way until a single-digit number is produced. The input will be a non-negative integer.

**Example:**

```
16 --> 1 + 6 = 7
942 --> 9 + 4 + 2 = 15 --> 1 + 5 = 6
132189 --> 1 + 3 + 2 + 1 + 8 + 9 = 24 --> 2 + 4 = 6
493193 --> 4 + 9 + 3 + 1 + 9 + 3 = 29 --> 2 + 9 = 11 --> 1 + 1 = 2
```

### My Solutions

#### Python

```
def digital_root(n: int) -> int:
n_str = str(n)
while len(n_str) > 1:
r = 0
for i in range(len(n_str)):
r = r + int(n_str[i])
n_str = str(r)
return n if (n >= 0 and len(str(n)) == 1) else r
```

#### JavaScript(TypeScript4)

```
export const digitalRoot = (n:number):number => {
return String(n).length == 1
? n : digitalRoot(
String(n).split("").map((n) => Number(n)).reduce(
(previousValue, currentValue) => previousValue + currentValue, 0)
)
};
```

## PHP

### Details

**Name Kata:** You're a square!

**7kuy**

**Description:** You like building blocks. You especially like building blocks that are squares. And what you even like more, is to arrange them into a square of square building blocks!

However, sometimes, you can't arrange them into a square. Instead, you end up with an ordinary rectangle! Those blasted things! If you just had a way to know, whether you're currently working in vain… Wait! That's it! You just have to check if your number of building blocks is a perfect square.

Task

Given an integral number, determine if it's a square number:

```
In mathematics, a square number or perfect square is an integer that is the square of an integer; in other words, it is the product of some integer with itself.
```

The tests will always use some integral number, so don't worry about that in dynamic typed languages.

**Example:**

```
-1 => false
0 => true
3 => false
4 => true
25 => true
26 => false
```

### My Solutions

```
function isSquare(int $n): bool {
return sqrt($n) == (int)sqrt($n) ? true : false;
}
```

## SQL

### Details

**Name Kata:** SQL Basics: Truncating

**7kuy**

**Description:** Given the following table 'decimals':

decimals table schema

```
id
number1
number2
```

Return a table with a single column towardzero where the values are the result of number1 + number2 truncated towards zero.

### My Solutions

```
SELECT TRUNC(number1 + number2) AS towardzero FROM decimals
```

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