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         	<h1 class="section-header">Values and Types</h1><hr>
			
			<p class="section-content">
			Gravity is a dynamically typed language so variables do not have a type, although they refer to a value that does have a type. In Gravity everything is an object (with methods you can call and instance variables you can use). Basic intrinsic types are of class Object, Int, Float, String, Bool, Null, <a href="classes.html">Class</a>, <a href="functions.html">Function</a>, Fiber, Instance, <a href="lists.html">List</a>, <a href="maps.html">Map</a> and Range.
			</p>
			
			<h4 class="section-h4">Object</h4>
			<p>Object is the root class of every object inside Gravity. Through the Object class, objects inherit a basic interface to the runtime system and the ability to behave as Gravity objects.</p>
			
			<h4 class="section-h4">Int</h4>
			<p>An Int represents a 64 bits (can optionally be compiled as 32bit) signed number:</p>
			<pre><code class="swift">
	var a = 123;		// decimal
	var b = 0xFF;		// hexadecimal
	var c = 0O7777;		// octal
	var d = 0B0101;		// binary
			</code></pre>
			
			<h4 class="section-h4">Float</h4>
			<p>A float represents a 32 bits (or better) floating point number:</p>
			<pre><code class="swift">
	var a = 3.1415;		// float
	var b = 1.25e2;		// scientific notation
			</code></pre>
			
			<h4 class="section-h4">String</h4>
			<p>Strings are an immutable sequence of characters. String literals can be surrounded in double or single quotes.</p>
			<pre><code class="swift">
	var a = "Hello World";	// double quotes
	var b = 'Hello World';	// single quotes
	
	// Strings have also a length property
	var n = b.length;	// n is now 11
			</code></pre>
			
			<h4 class="section-h4">Bool</h4>
			<p>The bool data type can have only two values, they are the literals true and false. A Bool value expresses the validity of a condition (tells whether the condition is true or false).</p>
			<pre><code class="swift">
	var a = true;
	var b = false;
			</code></pre>
			
			<h4 class="section-h4">Null</h4>
			<p>It indicates the absence of a value. If you call a method that doesn’t return anything and get its returned value, you get null back. The null data type is also used to initialize uninitialized variables with a default value.</p>
			<pre><code class="swift">
	class Newton {
		var mass = 10;
		var acceleration;
		func force() {
			return mass * acceleration;
		}
	}
			
	func f2() {
		var sir = Newton();
		// acceleration instance variable has no default value
		// so it is automatically set to null
		return sir.force();
	}
			
	func f1() {
		var a;
		// a is uninitialized so it has a default null value
		return a;
	}
			</code></pre>
			
			<h4 class="section-h4">Range</h4>
			<p>A range is an object that represents a consecutive range of numbers. Syntax for this type has been directly inspired by Swift.</p>
			<pre><code class="swift">
	// a represents a range with values 1,2,3
	var a = 1...3;
	
	// b represents a range with values 1,2
	var b = 1..<3;
	
	// Ranges have also a conveniente count property
	var n1 = a.count;	// n1 is now 3
	var n2 = b.count;	// n2 is now 2
			</code></pre>
			
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