Programming Languages & Structured Programming

Programming Languages:

• The language used in the communication of computer instruction is known as the Programming language.
•  The computer has its own language called binary language means computer can only understands binary language instructions. But it is very difficult to understand.
•  Normally all the programming languages are written into high-level languages like English languages.
• Some programming languages are C,C++,Java,Qbasic,vb.net etc.   

There are three levels of programming languages available.

1.  Machine language (low level languages)
2. Assembly (or symbolic) language
3. Procedure-oriented languages( high level languages)   

1.Machine Language:

•  Machine language means low level languages normally human can’t understand easily. This language includes binary code like o and 1 only.
• It is very difficult to understand.
• There is no need of any compiler.

Advantage:

• It is very fast language because there is no translation process

Disadvantages:

• It very difficult to understand
• Difficult to debug a program
• We need very deep knowledge of hardware   

2.Assembly Language:

• It is also known as symbolic language it includes some symbols and letters to write a program instead of writing a binary code.
• For example, ADD or A is used as a symbolic operation code represent addition and SUB or S is used for subtraction
• There was very difficult to write a code using binary code so the solution of this problem is Assembly language it uses some symbols and letters instead of writing a binary code
• Translator program is required to translate the Assembly Language to machine language. This translator program is called Assembler.
• It is considered to be a second-generation language.

Advantage:

• It is easy to understand compare to low level language
• Easy to debug a program

Disadvantages:

• We need very deep knowledge of hardware
• Slower compare to low level languages because it require assembler to conversion process.

3.High level Language:

• High level languages is more user friendly, human can easily understand this type of languages.  
• These languages consists of a set of words and symbols and one can write programs using these in conjunctions with certain rules like ‘ENGLISH’ language.
• It is like a English language so to understand to computer we need to convert it into low level language because computer can only understand low level language.
• So there  is compiler used to convert it into low level language
• The most important characteristics of a high level language is that it is machine independent and a program written in a high level language can be run on computers of different makes with little or no modification.

Advantage:

• It is very easy to understand compare to low level and Assembly language
• Easy to debug a program

Disadvantages:

•  Slower compare to low level and Assembly languages because it require Compiler or Interpreter to convert high level language into machine code.