By Anand George SourceLens.org Copyright. All rights reserved. Content Owner - Meera R (meera at sourcelens.org)

As we saw General nature of Computer programs.  Read or Write to computer memory.  Do operations on the data in the computer memory  Hand over the data to other parts of the program for more operations. SourceLens.org Copyright. All rights reserved. Content Owner - Meera R (meera at sourcelens.org)

Variables  In C program computer memory is accessed via “variables”.  Or variables in C program is a representation of computer memory.  Again Variables are nothing but memory so it remember things which we called values in the variable.  All variable store binary 1s and 0s as computer cannot remember anything else. SourceLens.org Copyright. All rights reserved. Content Owner - Meera R (meera at sourcelens.org)

Variable types  Based on size and type char, int, float, unsigned int and more ( custom).  Based on storage global, static, local or auto and register. One more storage class called thread local storage we wont discussion. SourceLens.org Copyright. All rights reserved. Content Owner - Meera R (meera at sourcelens.org)

Demo  char, int, float, unsigned int.  global, static, local or auto and register.  scope of variable. SourceLens.org Copyright. All rights reserved. Content Owner - Meera R (meera at sourcelens.org)

Remember  All variables are binary digits at the end of the day.  What makes each type different is just the way we interpret it. SourceLens.org Copyright. All rights reserved. Content Owner - Meera R (meera at sourcelens.org)

Questions  Why int is not used for representing English alphabets ? to save memory  Why we cannot use float always why we need int? to save CPU time. SourceLens.org Copyright. All rights reserved. Content Owner - Meera R (meera at sourcelens.org)

Demo  Interpreting int as char using %c  Looking at memory in visual studio char float and int.  Looking at memory to see the actual value stored. SourceLens.org Copyright. All rights reserved. Content Owner - Meera R (meera at sourcelens.org)

Summary  Variables types and classification.  All 1s and 0s.  All we interpret differently.  There is more but this is all we need for now. SourceLens.org Copyright. All rights reserved. Content Owner - Meera R (meera at sourcelens.org)

Thank you SourceLens.org Copyright. All rights reserved. Content Owner - Meera R (meera at sourcelens.org)