how to display file size in mb in linux code example

Example 1: ls human readable size

du -sh directory_name    #Gives you the summarized(-s) size of the directory in human readable(-h) format
du -bsh *                #Gives you the apparent(-b) summarized(-s) size of all the files and directories in the current directory in human readable(-h) format

Example 2: ls human readable size

ls -l filename   #Displays Size of the specified file
ls -l *          #Displays Size of All the files in the current directory
ls -al *         #Displays Size of All the files including hidden files in the current directory
ls -al dir/      #Displays Size of All the files including hidden files in the 'dir' directory