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Operators are symbols that perform special operations in programming. There are many different types of operators. The following chart illustrates these operators and their functions. Provided below is further explanation on how to use the different types of operators.
Arithmetic Operators
| Operator |
Action |
Examples
(int m=6; int n=2; int p=4; int ans;) |
| + |
Addition operator, adds two values |
ans = m + n;
//ans = 8
|
| - |
Subtraction operator, subtracts the second value from the first value |
ans = m - n;
//ans = 4 |
| * |
Multiplication operator, multiplies two values |
ans = 3 * 4;
//ans = 12 |
| / |
Division operator, divides the first value by the second value |
ans = m / n;
//ans = 3 |
| % |
Modulus operator, takes the remainder after simple division |
ans = m % n;
//ans = 0
ans = m % p;
//ans = 2
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Increment and Decrement Operators
| Operator |
Action |
Examples
(int m=6; int ans;) |
| ++ |
adds 1 to a variable |
m++;
//m = 7
This is equivalent to m = m +1 ;
ans = m++;
//ans = 6, m = 7
This increments the value of m AFTER it is used, therefore the value of ans is 6 and m is 7 . This is known as a postfix operator.
ans = ++m;
//ans = 7, m = 7
This increments the value of m BEFORE it is used, therefore the value of both ans and m is 7. This is known as prefix. |
| -- |
subtracts 1 from a variable |
Assignment Operators
| Operator |
Action |
Examples
(int m=6; int n=2; int ans;) |
| = |
assignment operator |
ans = m;
//ans = 6 |
| += |
adds the second value to the first variable |
m += 4;
//m = 10
This is equivalent to
m = m + 4;
m+=n;
//m=8
|
| -= |
subtracts the second value from the first variable |
m -= 4;
//m = 2
This is equivalent to
m = m - 4;
m -= n;
//m = 4 |
| *= |
multiplies the second value with the first variable |
m *= 4;
//m=24
This is equivalent to m = m * 4;
m *= n;
//m = 12 |
| /= |
divides the first variable by the second value |
m /= 4;
m = 1;
This is equivalent to m = m / 4; (Remember that int variables truncate decimals)
m /= n;
//m = 3 |
| %= |
performs modulo division on the first variable using the second value |
m %= 4;
//m = 2
This equivalent to
m = m % 4;
m /= n;
//m = 0 |
Dot Operator
| Operator |
Action |
Examples
|
| . |
calls a method of a class |
circle.area();
This calls the area method of the Circle class to calculate the area of a circle.
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New Operator
| Operator |
Action |
Examples
(int m=6; int n=2; int ans;) |
| new |
creates an new array or object of a class |
int [] numbers = new int [10];
This creates a new array called numbers.
Circle c = new Circle();
This creates a new instance of the Circle object.
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Relational and Logical Operators
All the following conditions return a boolean answer (true or false).
| Operator |
Action |
Example
(int m=6; int n=2; boolean flag=true;) |
| > |
greater than |
if (m > n) { ... }
The value of the conditional statement (m>n) is true. |
| >= |
greater than or equal to |
| < |
less than |
| <= |
less than or equal to |
| == |
equal |
if (m == n) { ...
}
The value of the conditional statement (m == n) is false.
boolean x = (m != n);
The value of x becomes the value of the conditional statement (m != n), which is true. |
| != |
not equal |
| ! |
not; inverts the value of a boolean |
if (!flag)
...
This means that if flag is false, then... |
Note: the "=" operator means assigning a value to a variable, while the "==" operator is comparing if one value is equal to another value.
Conditional Operators
| Operator |
Action |
Example |
| && |
and |
If (m==1 && n==2)
...
This means that if both conditions are true (m=1 and n=2) then... |
| || |
or |
If (m==1 || n==2)
...
This means that if either condition is true or both are true (m=1 or n=2 or both) then... |
Operator Precedence
When there are a few operators written in the same line of code, some operators are considered before others. That is what is called operator precedence. The operator precedence from highest to lowest is:
--/++(postfix), --/++(prefix), !, /, *, %, +, -, <, <=, >, >=, ==, !=, &&, ||
Related Links
There are a couple more operators that we haven't discussed. Although they may not be strictly neccessary for your purposes, you should be aware of their existance. For more information on these operators, check out some useful links:
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