Pure and View Function DEV by Solidity

View functions ensure that they will not modify the state, compiler will throw warning in such cases:

• Modifying state variables.
• Emitting events.
• Creating other contracts.
• Using selfdestruct.
• Sending Ether via calls.
• Calling any function which is not marked view or pure.
• Using low-level calls.
• Using inline assembly containing certain opcodes

Pure functions ensure that they not read or modify the state, compiler will throw warning in such cases.

• Reading state variables.
• Accessing address(this).balance or <address>.balance.
• Accessing any of the special variable of block, tx, msg (msg.sig and msg.data can be read).
• Calling any function not marked pure.
• Using inline assembly that contains certain opcodes.