Verify that the input meets the criteria

Break jumps out of the loop closest to it. such as while, for

Verify that the five letters you entered are uppercase.

 Public Static voidMain (string[] args) {Console.WriteLine ("Please enter five uppercase letters:");  while(true) {//Loop until it is entered correctly                BOOLA =true; stringstr =console.readline ();//The input defaults to a string.                If the data is int, then Convert.ToInt32 (str);  for(inti =0; I <5; i++) {                    if(Str[i] >='A'&& Str[i] <='Z') {//characters are stored as int data, character equivalent data//empty statement, no action}Else{a=false;  Break;//Once there is a lowercase letter, jump out of the For Loop                    }                }                if(A = =true) {Console.WriteLine ("Enter the correct");  Break;//Jump out while loop}Else{Console.WriteLine ("have lowercase letters, input errors, please re-enter");        }} console.readkey (); }

Verify that the input meets the criteria