Restrictions for modifying variables in the Monitor window

You can modify the value of a variable by typing over the existing value in the Monitor window, with the following exceptions:

  • You cannot type in a value that is larger than the declared type of the variable. For example, if you declare a variable as a string of four character and you try to type in five characters, z/OS® Debugger prevents you from typing in the fifth character.
  • If z/OS Debugger cannot display the entire value in the Monitor window and the setting of MONITOR WRAP is ON, you cannot modify the value of that variable.
  • If you modify a long value and the setting of MONITOR WRAP is OFF, z/OS Debugger creates a STORAGE command to modify the value. If you are debugging a program that is optimized, the STORAGE command might not modify the value.
  • You cannot modify the value of z/OS Debugger variables, except value of registers %GPRn, %FPRn, %EPRn, %LPRn.
  • You cannot modify the value of a z/OS Debugger built-in function.
  • You cannot modify the value of a PL/I built-in function.
  • You cannot modify a complex expression.

If you type quotation marks (") or apostrophes (') in the Monitor value area, carefully verify that they comply with any applicable quotation rules.