# 2.2. Values and Data types¶

daScript is a strong statically typed language and all variables do have a type. daScript’s basic POD (plain old data) data types are:

```int, uint, float, bool, double, int64, uint64
int2, int3, int4, uint2, uint3, uint4, float2, float3, float4
```

All PODs are represented with machine register/word. All PODs will be passed to function argument by value.

daScript’s storage types (which can’t be manipulated with, but can be used as storage type within structs or otherwise):

```int8, uint8, int16, uint16 - 8/16-bits signed and unsigned integers
```

daScript’s other types are:

```string, das_string, struct, pointers, references, block, lambda, function pointer, array, table
```

all daScript’s types are initialized with zero memory by default.

## 2.2.1. Integer¶

An Integer represents a 32-bit (un)signed number:

```let a = 123    // decimal, integer
let u = 123u   // decimal, unsigned integer
let h = 0x0012 // hexadecimal, unsigned integer
let o = 075    // octal, unsigned integer

let a = int2(123, 124)    // two integers type
let u = uint2(123u, 124u) // two unsigned integer type
```

## 2.2.2. Float¶

A float represents a 32-bit floating point number:

```let a = 1.0
let b = 0.234
let a = float2(1.0, 2.0)
```

## 2.2.3. Bool¶

Bool is a double-valued (Boolean) data type. Its literals are `true` and `false`. A bool value expresses the validity of a condition (tells whether the condition is true or false):

```let a = true
let b = false
```

All conditions (if, elif, while) works only on bool type.

## 2.2.4. String¶

Strings are an immutable sequence of characters. In order to modify a string is it necessary create a new one.

daScript’s strings are similar to strings in C or C++. They are delimited by quotation marks(`"`) and can contain escape sequences (`\t`, `\a`, `\b`, `\n`, `\r`, `\v`, `\f`, `\\`, `\"`, `\'`, `\0`, `\x<hh>`, `\u<hhhh>` and `\U<hhhhhhhh>`):

```let a = "I'm a string\n"
```

Strings type can be thought of as ‘pointer to actual string’ type, like ‘const char *’ in C language. As such they will be passed to function argument by value (but this value is just reference to immutable string in memory).

das_string - is mutable string, which content can be changed. It is simply builtin handled type, i.e., std string bound to daScript. As such, it passed as reference.

## 2.2.5. Table¶

Tables are associative containers implemented as a set of key/value pairs:

```var tab: table<string; int>
tab["10"] = 10
tab["20"] = 20
tab["some"] = 10
tab["some"] = 20 // replaces the value for 'some' key
```

(see Tables).

## 2.2.6. Array¶

Arrays are simple sequence of objects. There are static arrays (fixed size), and dynamic array (container, size is dynamic) and index always starts from 0:

```var a = [[int 1; 2; 3; 4]] // fixed size of array is 4, and content is [1, 2, 3, 4]
var b: array<string>          // empty dynamic array
push(b,"some")                // now it is 1 element of "some"
```

(see Arrays).

## 2.2.7. Struct¶

Structs are record of data of other types (including structs), similair to C language. All structs (as well as other non-POD types, except strings) will be passed by reference

(see Structs).

## 2.2.8. Tuple¶

Tuple are anonimous record of data of other types (including structs), similair to C++ std::tuple. All tuples (as well as other non-POD types, except strings) will be passed by reference

(see Tuples).

## 2.2.9. Function¶

Functions are similar to those in most other languages:

```def twice(a: int): int
return a + a
```

However, there are generic (templated) functions, which will be ‘instantiated’ during compilation of call to them.

```def twice(a)
return a + a

let f = twice(1.0) // 2.0 float
let i = twice(1)   // 2 int
```

(see Functions).

## 2.2.10. Reference¶

References are types that ‘references’ (points) some other data.

```def twice(a: int&)
a = a + a
var a = 1
twice(a) // a value is now 2
```

All structs are always passed to functions arguments as references.

## 2.2.11. Pointers¶

Pointers are types that ‘references’ (points) some other data, but can be null (points to nothing). In order to work with actual value, one need to dereference using deref builtin function them or use safe navigation operators. deref will panic, if null pointer is passed to it. Pointers can be created using new operator, or with C++ environment.

```def twice(a: int&)
a = a + a
def twicePointer(a: int?)
twice(deref(a))

struct Foo
x: int

def getX(foo: Foo?)  // it returns either foo.x or -1, if foo is null
return foo?.x ?? -1
```

All structs are always passed to functions arguments as references.

## 2.2.12. Iterators¶

Iterator is an entity which can be travered, and associated data retrived. It is similar to C++ iterators.

(see Iterators).