Java loops and conditional statements

...
if ( condition )     // The condition is a boolean expression
        statement;    // Executes if condition is true
                      // No enclosing block is required when only one statement
    [ else {
        statement;    // Executes if condition is false
        statement;    // Enclosing block is necessary when more than one statement
    }
    ]
...

public class IfelseExample {

  public static void main(String[] args) {
    int[] numbers = {10, 72, 300};
    for (int num : numbers) {
      if (num > 100) {
        System.out.println(num+ " is grater than 100");
      } else if (num > 50) {
        System.out.println(num+ " is grater than 50");
      } else {
        System.out.println(num+ " is less than 50");
      }
    }
  }
}

// First the syntax
// (expression1) ? (expression2) : (expression3)
...
int z =  (x < y) ? x : y;
// When x > y  then z=x else z=y
...

// The while syntax
while ( condition ){
        statement;  // Statements executes as long as condition is true
        statement;   
}
// This is the do-while syntax
do  {
   statement;       // do-while loop always executes 
   statement;       // its statement body at least once.
   statement;       // Statements executes as long as condition is true
 }
 while ( condition );

public class Whiledemo {
    public static void main(String[] args) {
    int[] numbers = {10, 72, 300};
    int num=0;
    while(num<numbers.length) {
      if (numbers[num] > 100) {
        System.out.println(numbers[num]+ " is grater than 100");
      } else if (num > 50) {
        System.out.println(numbers[num]+ " is grater than 50");
      } else {
        System.out.println(numbers[num]+ " is less than 50");
      }
      num++;
    }
  }
}

...
for ( initialization; condition; incrementor )
    statement;
// Initialization are limited to the scope of the for statement
// The condition is a boolean expression (if true the body is executed)
// Following each execution of the body, the incrementor expressions are evaluated.  
...

// Use of  multiple comma-separated
// expressions in the initialization
// and in the incrementation sections.
for (int i = 0, j = 100; i < 100; i++, j-- ) {
  System.out.println( i  );      
  System.out.println( j  );     
}                               
...
int x; // Initialize existing variables from outside the scope of the for loop 
for( x = 0; hasMoreValue(  ); x++ ) // In this case a method 
   getNextValue(  );                // is returning the condition
System.out.println( x );
...

...
for ( varDeclaration : iterable )
        statement;
// Iterating over a series of values in an array
// or other type of collection
...
int [] arrayOfInts = new int [] { 1, 2, 3, 4 };

for( int i : arrayOfInts )
  System.out.println( i );

// In this example the enhanced for loop will 
// print all the values in array, arrayOfInts. 
...

...
for ( initialization; condition; incrementor )
    statement;
switch ( int expression )
 {
     case int constantExpression :
         statement; break;
     [ case int constantExpression
         statement; break; ]
     ...
     [ default :
         statement;  ]
 }
...

public class SwitchDemo {

  public static void main(String[] args) {
    for (int mnd = 1; mnd <= 6; mnd++) {
      int days = 31;
      switch (mnd) {
        case 2:
          days = 29;
          break;
        case 4:
        case 6:
          days = 30;
          break;
      }
      for (int day = 1; day <= days; day++) {
        String  pre="";
        if (day<10) {
          pre="0";
        }
        System.out.print(pre+day + "." + mnd + "." + "2008 ");
        if (day % 10 == 0){
          System.out.println();
        }
      }
      System.out.println();
    }
  }

...
while( true ) {
        if ( condition(  ) )
             break;
    }
    // after while
...

...
for( int i=0; i < 100; i++ ) {
        if ( i == 33 )
            continue;
        System.out.println( i );
    }

...