Comparison of programming languages (basic instructions)

Data types

How to declare variable x as the following types:

	Integer	Unsigned integer	Float	String
C	int x;	unsigned int x;	float x; or double x;	char x[]; or char *x;
C++ (STL)	int x;	unsigned int x;	float x; ordouble x;	string x;
Java				String x; (???)
Pascal	var x: integer;		var x: real;	var x: string;
Visual Basic	dim x as integer
Python	x = value	x = value	x = value	x = "string"

Logical cycles

	if	else if	while	for i = 1 to N	select case
C	if (condition) { instructions } else { instructions }	if (condition) { instructions } else if (condition) { instructions }	while (condition) { instructions }	for (i = 0; i<N; i++) { instructions }	switch (variable) { case case1: instructions break; ... }
C++ (STL)	as above	as above	as above	as above	as above
Java	as above	as above	as above	as above	as above
Pascal	if condition then begin \n instructions \n end;		repeat \n instructions \n until condition;	for i := 1 to N do \n begin \n instructions \n end;
Visual Basic	if condition then \n instructions \n end if		while condition \n instructions \n wend	for i = 1 to N step 1 \n instructions \n next
Python	if condition : \n \t instructions \n else: \n \tinstructions \n			for i in range(1, N): \n \t instructions \n

Function declaration

	basic	value-returning function
C	void foo(parameters) { }	typefoo(parameters) { }
C++ (STL)	as above	as above
Java	public or private + as above	public or private +as above
Pascal	procedure foo(...);	function foo(...):type;
Visual Basic
Python	def foo(parameters): \n \t instructions \n	add return value at the end.

Data conversions

	string to integer	string to float	integer to string	float to string
C	integer = atoi(string);	float = atof(string);	sprintf(string, "%i", integer);	sprintf(string, "%f", float);
C++
Java
Pascal
Visual Basic
Python