java - Declaring variable and assignment -

i practicing java program in eclispe following code:

import java.util.*; class problem7 {     public static void main(string args[]){ int num,sum=0,mod_num,count;//syntax error on token ";", { expected after                                         //this token. ques=why? system.out.println("enter 5 digit number"); try(scanner n1 = new scanner(system.in)) {     num = n1.nextint(); } for(count = 0; count <= 4; count=count+1) {         mod_num = num%10;         num=num/10;         sum = sum+mod_num; } system.out.println("the sum off digits "+sum); } } 

========================================================================== above code runs correctly without error. if wanted use different class "class sum_of_digits" following code. starts shows error in class "sum_of_digits" before create object.following code:

import java.util.*; class sum_of_digits { int num,sum=0,mod_num,count;//syntax error on token ";", { expected after                                         //this token. ques=why? for(count = 0; count <= 4; count=count+1) {         mod_num = this.num%10;         this.num=this.num/10;         sum = sum+mod_num; } system.out.println("the sum off digits "+sum); } 

====================================================================== if include loop in method , make necessary arrangements, code works fine, runs without error , desired result: below new code class "sum_of_digits":

import java.util.*; class sum_of_digits { int num,sum=0,mod_num,count;//syntax error on token ";", { expected after                                //this token void loop() {     for(count = 0; count <= 4; count=count+1)     {         mod_num = this.num%10;         this.num=this.num/10;         sum = sum+mod_num;     }     system.out.println("the sum off digits "+sum); } }  class problem7  { public static void main(string args[]) {     sum_of_digits digit = new sum_of_digits();     system.out.println("enter 5 digit number");     try(scanner n1 = new scanner(system.in))     {         digit.num = n1.nextint();     }     digit.loop(); } } 

my question why cant declare loop directly in class "sum_of_digits"?

you've got loop in class body. it's not allowed here.

class sum_of_digits {     int num, sum=0, mod_num, count;      for(count = 0; count <= 4; count=count+1)     {      } } 

executable statements need in method, constructor, or initializer block.

class sum_of_digits {     int num, sum=0, mod_num, count;      void loop() {         for(count = 0; count <= 4; count=count+1)         {          }     } }