Scala operator

An operator is a symbol, used to tell the compiler to perform a specified mathematical and logical operations.

Scala rich built-in operators, including the following types:

• Arithmetic operators

• Relational Operators

• Logical Operators

• Bitwise Operators

• Assignment Operators

Next, we will explain to you more than the application of various operators.

Arithmetic operators

The following table lists the Scala support arithmetic operators.

A variable assumed as 10, B 20:

Examples

object Test {
   def main(args: Array[String]) {
      var a = 10;
      var b = 20;
      var c = 25;
      var d = 25;
      println("a + b = " + (a + b) );
      println("a - b = " + (a - b) );
      println("a * b = " + (a * b) );
      println("b / a = " + (b / a) );
      println("b % a = " + (b % a) );
      println("c % a = " + (c % a) );
      
   }
}

Running instance »

Implementation of the above code, the output is:

$ scalac Test.scala 
$ scala Test
a + b = 30
a - b = -10
a * b = 200
b / a = 2
b % a = 0
c % a = 5

Relational Operators

The following table lists the Scala support relational operators.

A variable assumed as 10, B 20:

Examples

object Test {
   def main(args: Array[String]) {
      var a = 10;
      var b = 20;
      println("a == b = " + (a == b) );
      println("a != b = " + (a != b) );
      println("a > b = " + (a > b) );
      println("a < b = " + (a < b) );
      println("b >= a = " + (b >= a) );
      println("b <= a = " + (b <= a) );
   }
}

Implementation of the above code, the output is:

$ scalac Test.scala 
$ scala Test
a == b = false
a != b = true
a > b = false
a < b = true
b >= a = true
b <= a = false

Logical Operators

The following table lists the Scala supports logical operators.

A variable assumed as 1, B is 0:

Examples

object Test {
   def main(args: Array[String]) {
      var a = true;
      var b = false;

      println("a && b = " + (a&&b) );

      println("a || b = " + (a||b) );

      println("!(a && b) = " + !(a && b) );
   }
} 

Implementation of the above code, the output is:

$ scalac Test.scala 
$ scala Test
a && b = false
a || b = true
!(a && b) = true

Bitwise Operators

Bitwise Operators bits used to operate, ~, &, |, ^ were negated, and the bit, or by bit and, bitwise XOR operation with the following table examples:

If A = 60; and B = 13; two variables corresponding to binary is:

A = 0011 1100

B = 0000 1101

-------位运算----------

A&B = 0000 1100

A|B = 0011 1101

A^B = 0011 0001

~A  = 1100 0011

The Scala Bitwise rule as follows:

Examples

object Test {
   def main(args: Array[String]) {
      var a = 60;           /* 60 = 0011 1100 */  
      var b = 13;           /* 13 = 0000 1101 */
      var c = 0;

      c = a & b;            /* 12 = 0000 1100 */ 
      println("a & b = " + c );

      c = a | b;            /* 61 = 0011 1101 */
      println("a | b = " + c );

      c = a ^ b;            /* 49 = 0011 0001 */
      println("a ^ b = " + c );

      c = ~a;               /* -61 = 1100 0011 */
      println("~a = " + c );

      c = a << 2;           /* 240 = 1111 0000 */
      println("a << 2 = " + c );

      c = a >> 2;           /* 215 = 1111 */
      println("a >> 2  = " + c );

      c = a >>> 2;          /* 215 = 0000 1111 */
      println("a >>> 2 = " + c );
   }
} 

Implementation of the above code, the output is:

$ scalac Test.scala 
$ scala Test
a & b = 12
a | b = 61
a ^ b = 49
~a = -61
a << 2 = 240
a >> 2  = 15
a >>> 2 = 15

Assignment Operators

The following lists the Scala language support assignment operator:

Examples

object Test {
   def main(args: Array[String]) {
      var a = 10;	
      var b = 20;
      var c = 0;

      c = a + b;
      println("c = a + b  = " + c );

      c += a ;
      println("c += a  = " + c );

      c -= a ;
      println("c -= a = " + c );

      c *= a ;
      println("c *= a = " + c );

      a = 10;
      c = 15;
      c /= a ;
      println("c /= a  = " + c );

      a = 10;
      c = 15;
      c %= a ;
      println("c %= a  = " + c );

      c <<= 2 ;
      println("c <<= 2  = " + c );

      c >>= 2 ;
      println("c >>= 2  = " + c );

      c >>= 2 ;
      println("c >>= a  = " + c );

      c &= a ;
      println("c &= 2  = " + c );
     
      c ^= a ;
      println("c ^= a  = " + c );

      c |= a ;
      println("c |= a  = " + c );
   }
} 

Implementation of the above code, the output is:

$ scalac Test.scala 
$ scala Test
c = a + b  = 30
c += a  = 40
c -= a = 30
c *= a = 300
c /= a  = 1
c %= a  = 5
c <<= 2  = 20
c >>= 2  = 5
c >>= a  = 1
c &= 2  = 0
c ^= a  = 10
c |= a  = 10

Operator Precedence

In an expression may contain a plurality of different operators connecting with different data types of data objects; since the expression has a variety of operations, a different order of operations may have different results even erroneous operation error, because when when an expression containing a variety of operations, according to a certain order must be combined in order to ensure the rationality and correctness of the results, the uniqueness of operation.

Priority in descending order from top to bottom, the top has the highest priority, the comma operator has the lowest priority.

The same priority level, according to the binding order of calculation. Most operations are calculated from left to right, only three priorities are right-to-left combination, they are unary operators, conditional operators, assignment operators.

The basic priorities need to remember:

• Optimal pointer, unary than binary operators. As the sign.
• First multiplication and division (modulus) after subtraction.
• First arithmetic shift operation after the last bit computing. Please pay particular attention to: << 1 2 & 3 + 7 is equivalent to (1 << (3 + 2)) & 7
• Final calculation logic operation