- 4 years ago
- Afaq Arif
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In this chapter, we will discuss in detail about types of different operators used in TypeScript.
What is an Operator?
An operator defines some functions that will be performed on the data. The data on which operators perform are operands. Consider the following expression.
7 + 5 = 12
Here, the values 7, 5, and 12 are operands, while + and = are operators.
The major operators in TypeScript can be classified as.
- Arithmetic operators
- Logical operators
- Relational operators
- Bitwise operators
- Assignment operators
- Ternary/conditional operator
- String operator
- Type Operator
Arithmetic Operators
Let us suppose the values in variables a and b are 10 and 5 respectively.
| Operator | Description | Example |
|---|
| + (Addition) | returns the sum of the operands | a + b is 15 |
| – (Subtraction) | returns the difference of the values | a – b is 5 |
| * (Multiplication) | returns the product of the values | a * b is 50 |
| / (Division) | performs division operation and returns the quotient | a / b is 2 |
| % (Modulus) | performs division operation and returns the remainder | a % b is 0 |
| ++ (Increment) | Increments the value of the variable by one | a++ is 11 |
| — (Decrement) | Decrements the value of the variable by one | a– is 9 |
Relational Operators
Relational Operators define the type of relationship between two operations. These operators return a Boolean value that can be true or false.
Now suppose the value of A is 10 and B is 20.
| Operator | Description | Example |
|---|
| > | Greater than | (A > B) is False |
| < | Lesser than | (A < B) is True |
| >= | Greater than or equal to | (A >= B) is False |
| <= | Lesser than or equal to | (A <= B) is True |
| == | Equality | (A == B) is false |
| != | Not equal | (A != B) is True |
Logical Operators
When we need to combine two or more conditions, Logical Operators are used. These operators can also return a Boolean value. Suppose the value of variable A is 10 and B is 20.
| Operator | Description | Example |
|---|
| && (And) | The operator returns true only if all the expressions specified return true | (A > 10 && B > 10) is False |
| || (OR) | The operator returns true if at least one of the expressions specified return true | (A > 10 || B >10) is True |
| ! (NOT) | The operator returns the inverse of the expression’s result. For E.g.: !(>5) returns false | !(A >10 ) is True |
Bitwise Operators
Take variable A = 2 and B = 3
| Operator | Description | Example |
|---|
| & (Bitwise AND) | It performs a Boolean AND operation on each bit of its integer arguments. | (A & B) is 2 |
| | (BitWise OR) | It performs a Boolean OR operation on each bit of its integer arguments. | (A | B) is 3 |
| ^ (Bitwise XOR) | It performs a Boolean exclusive OR operation on each bit of its integer arguments. Exclusive OR means that either operand one is true or operand two is true, but not both. | (A ^ B) is 1 |
| ~ (Bitwise Not) | It is a unary operator and operates by reversing all the bits in the operand. | (~B) is -4 |
| << (Left Shift) | It moves all the bits in its first operand to the left by the number of places specified in the second operand. New bits are filled with zeros. Shifting a value left by one position is equivalent to multiplying it by 2, shifting two positions is equivalent to multiplying by 4, and so on. | (A << 1) is 4 |
| >> (Right Shift) | Binary Right Shift Operator. The left operand’s value is moved right by the number of bits specified by the right operand. | (A >> 1) is 1 |
| >>> (Right shift with Zero) | This operator is just like the >> operator, except that the bits shifted in on the left are always zero. | (A >>> 1) is 1 |
Assignment Operators
| Operator | Description | Example |
|---|
| = (Simple Assignment) | Assigns values from the right side operand to the left side operand | C = A + B will assign the value of A + B into C |
| += (Add and Assignment) | It adds the right operand to the left operand and assigns the result to the left operand. | C += A is equivalent to C = C + A |
| -= (Subtract and Assignment) | It subtracts the right operand from the left operand and assigns the result to the left operand. | C -= A is equivalent to C = C – A |
| *= (Multiply and Assignment) | It multiplies the right operand with the left operand and assigns the result to the left operand. | C *= A is equivalent to C = C * A |
| /= (Divide and Assignment) | It divides the left operand with the right operand and assigns the result to the left operand. | |
Note − Same logic applies to Bitwise operators, so they will become <<=, >>=, >>=, &=, |= and ^=.
Miscellaneous Operators
The negation operator (-)
Changes the sign of a value. Let’s take an example.
var x:number = 4
var y = -x;
console.log("value of x: ",x); //outputs 4
console.log("value of y: ",y); //outputs -4
The following JavaScript will run on composing.
//Generated by typescript 1.8.10
var x = 4;
var y = -x;
console.log("value of x: ", x); //outputs 4
console.log("value of y: ", y); //outputs -4
It will show the following result.
value of x: 4
value of y: -4
String Operators: Concatenation operator (+)
When we apply + operator to strings, it will add the second string to the first. The following example helps us to understand this concept.
var msg:string = "hello"+"world"
console.log(msg)
The following JavaScript will run on composing.
//Generated by typescript 1.8.10
var msg = "hello" + "world";
console.log(msg);
It will show the following output.
The concatenation operation doesn’t add a space between strings. We can concatenate multiple strings in a single statement.
Conditional Operator (?)
This operator shows a conditional expression. The conditional operator is also sometimes mentioned as the ternary operator. The syntax is as given below.
- Test − refers to the conditional expression
- expr1 − the value returned if the condition is true
- expr2 − the value returned if the condition is false
Let’s see at the following code.
var num:number = -2
var result = num > 0 ?"positive":"non-positive"
console.log(result)
Line 2 checks whether the value in the variable num is greater than zero. If we set num to a value greater than zero, it will return the string “positive” else the string “non-positive” is returned.
The following JavaScript will run on composing.
//Generated by typescript 1.8.10
var num = -2;
var result = num > 0 ? "positive" : "non-positive";
console.log(result);
It will show the following output.
Type Operators
typeof operator
It is a unary operator that returns the data type of the operand. Take a look at the following example.
var num = 12
console.log(typeof num); //output: number
The following JavaScript will run on composing.
//Generated by typescript 1.8.10
var num = 12;
console.log(typeof num); //output: number
It will show the following output.
instanceof
This operator checks if an object is of a specified type or not. The use of instanceof the operator is discussed in the chapter classes.
- 4 years ago
- Afaq Arif
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