Data types

Melang is a implicit-type script language. So you don’t have to give variable’s type in code.

But every value has its type. Types in Melang are shown below:

• integer
• real
• boolean
• string
• nil
• array
• set
• object
• function

e.g.

// this is a comment line (start with two slashs)
/*...*/ this is a comment block (start with /* end with */)

//variable i has an integer value
i = 1;

//f has a real value
f = 1.2;

//b has a boolean value
b = true;

//n's value is nil, and nil means none
n = nil;

//[1, 2] is an array with two elements (1 and 2)
a = [1, 2];

//the value of d is a dict but in melang dict is a kind of array
d = ['age': 18, 'name': 'Mr. M'];

//human is a set, it's equivalent to Structure in C, but it supports function definition
human {
  name;
  age;
  @run () { // this is a method definition.
    //...
  }
}

//value of o is an object or instance of set human.
o = $human;

//access object properties
o.name;
o.age = 1;

//accessing non-existent object properties
o.gender // nil will be given
o.phone_number = 123; // the value of the new property `phone_number` has been set to 123.

//here is a function definition
@foo()
{
  //...
}

// and here is a function call
foo();

Array

Array is a kind of data set. If we want to get or access its elements, we can do it as shown below:

a = [1, 2, 3];

a[0]; //array[index]

a[0] retrieves the first element 1 from the array a, while a[2] retrieves the last element 3.

If the index is greater than or equal to the array length, nil will be given.

There is another kind of array named dict.

d = ['name': 'Tom', 'age': 18];

Now if we want to access the element which key is name, we can do it in this way:

d['name']; //dict[key]

If key is not in this dict, nil will be given.