Mastering Blockchain - Second Edition

Control structures

Control structures available in solidity language are if...else, do, while, for, break, continue, and return. They work exactly the same as other languages such as C-language or JavaScript.

Some examples are shown here:

• if: If x is equal to 0 then assign value 0 to y else assign 1 to z:

      if (x == 0) 
          y = 0; 
      else 
          z = 1; 

• do: Increment x while z is greater than 1:

      do{ 
          x++; 
      } (while z>1); 

• while: Increment z while x is greater than 0:

      while(x > 0){ 
          z++; 
      } 

• for, break, and continue: Perform some work until x is less than or equal to 10. This for loop will run 10 times, if z is 5 then break the for loop:

      for(uint8 x=0; x<=10; x++) 
      { 
          //perform some work 
          z++ 
          if(z == 5) break; 
      } 

It will continue the work similarly, but ...