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📜  TypeScript运算符

📅  最后修改于: 2021-01-11 12:23:02             🧑  作者: Mango

TypeScript运算符

运算符是对值或数据进行运算的符号。它表示处理数据的特定操作。运算符操作的数据称为操作数。它可以与一个或多个值一起使用以产生单个值。 TypeScript程序可使用所有标准JavaScript运算符。

例

10 + 10 = 20;

在上面的示例中，值“ 10”和“ 20”被称为操作数，而值“ +”和“ =”被称为运算符。

TypeScript中的运算符

在TypeScript中，可以将运算符分为以下几种方式。

算术运算符

算术运算运算符将数字值作为其操作数，执行一个操作，然后返回一个数字值。最常见的算术运算运算符是加法(+)，减法(-)，乘法(*)和除法(/)。

Operator Operator_Name Description Example
+ Addition It returns an addition of the values. 
let a = 20;
let b = 30;
let c = a + b;
console.log( c ); //
Output
30
– Subtraction It returns the difference of the values. 
let a = 30;
let b = 20;
let c = a - b;
console.log( c ); //
Output
10
* Multiplication It returns the product of the values. 
let a = 30;
let b = 20;
let c = a * b;
console.log( c ); //
Output
600
/ Division It performs the division operation, and returns the quotient. 
let a = 100;
let b = 20;
let c = a / b;
console.log( c ); //
Output
5
% Modulus It performs the division operation and returns the remainder. 
let a = 95;
let b = 20;
let c = a % b;
console.log( c ); //
Output
15
++ Increment It is used to increments the value of the variable by one. 
let a = 55;
a++;
console.log( a ); //
Output
56
— Decrement It is used to decrements the value of the variable by one. 
let a = 55;
a--;
console.log( a ); //
Output
54

比较(关系)运算符

运算符用于将两个操作数进行比较。这些运算符返回布尔值true或false。最重要的比较运算符如下。

Operator Operator_Name Description Example
== Is equal to It checks whether the values of the two operands are equal or not. 
let a = 10;
let b = 20;
console.log(a==b);     //false
console.log(a==10);    //true
console.log(10=='10'); //true
=== Identical(equal and of the same type) It checks whether the type and values of the two operands are equal or not. 
let a = 10;
let b = 20;
console.log(a===b);    //false
console.log(a===10);   //true
console.log(10==='10'); //false
!= Not equal to It checks whether the values of the two operands are equal or not. 
let a = 10;
let b = 20;
console.log(a!=b);     //true
console.log(a!=10);    //false
console.log(10!='10'); //false
!== Not identical It checks whether the type and values of the two operands are equal or not. 
let a = 10;
let b = 20;
console.log(a!==b);     //true
console.log(a!==10);    /false
console.log(10!=='10'); //true
> Greater than It checks whether the value of the left operands is greater than the value of the right operand or not. 
let a = 30;
let b = 20;
console.log(a>b);     //true
console.log(a>30);    //false
console.log(20> 20'); //false
>= Greater than or equal to It checks whether the value of the left operands is greater than or equal to the value of the right operand or not. 
let a = 20;
let b = 20;
console.log(a>=b);     //true
console.log(a>=30);    //false
console.log(20>='20'); //true
< Less than It checks whether the value of the left operands is less than the value of the right operand or not. 
let a = 10;
let b = 20;
console.log(a
<= Less than or equal to It checks whether the value of the left operands is less than or equal to the value of the right operand or not. 
let a = 10;
let b = 20;
console.log(a<=b);     //true
console.log(a<=10);    //true
console.log(10<='10'); //true

逻辑运算符

逻辑运算符用于将两个或多个条件组合为单个表达式，并返回布尔结果true或false。逻辑运算符如下。

Operator Operator_Name Description Example
&& Logical AND It returns true if both the operands(expression) are true, otherwise returns false. 
let a = false;
let b = true;
console.log(a&&b);      /false
console.log(b&&true);   //true
console.log(b&&10);     //10 which is also 'true'
console.log(a&&'10');  //false
|| Logical OR It returns true if any of the operands(expression) are true, otherwise returns false. 
let a = false;
let b = true;
console.log(a||b);      //true
console.log(b||true);   //true
console.log(b||10);     //true
console.log(a||'10');   //'10' which is also 'true'
! Logical NOT It returns the inverse result of an operand(expression). 
let a = 20;
let b = 30;
console.log(!true);    //false
console.log(!false);   //true
console.log(!a);       //false
console.log(!b);       /false
console.log(!null);    //true

按位运算符

按位运算运算符对操作数执行按位运算。按位运算运算符如下。

Operator Operator_Name Description Example
& Bitwise AND It returns the result of a Boolean AND operation on each bit of its integer arguments. 
let a = 2;
let b = 3;
let c = a & b;
console.log(c);   //
Output
2
| Bitwise OR It returns the result of a Boolean OR operation on each bit of its integer arguments. 
let a = 2;
let b = 3;
let c = a | b;
console.log(c);   //
Output 
3
^ Bitwise XOR It returns the result of a Boolean Exclusive OR operation on each bit of its integer arguments. 
let a = 2;
let b = 3;
let c = a ^ b;
console.log(c);   //
Output 
1
~ Bitwise NOT It inverts each bit in the operands. 
let a = 2;
let c = ~ a;
console.log(c);   //
Output 
-3
>> Bitwise Right Shift The left operand’s value is moved to the right by the number of bits specified in the right operand. 
let a = 2;
let b = 3;
let c = a >> b;
console.log(c);   //
Output 
0
<< Bitwise Left Shift The left operand’s value is moved to the left by the number of bits specified in the right operand. New bits are filled with zeroes on the right side. 
let a = 2;
let b = 3;
let c = a << b;
console.log(c);   //
Output 
16
>>> Bitwise Right Shift with Zero The left operand’s value is moved to the right by the number of bits specified in the right operand and zeroes are added on the left side. 
let a = 3;
let b = 4;
let c = a >>> b;
console.log(c);   //
Output 
0

赋值运算符

赋值运算符用于为变量赋值。赋值运算符的左侧称为变量，而赋值运算符的右侧称为值。变量和值的数据类型必须相同，否则编译器将引发错误。赋值运算符如下。

Operator Operator_Name Description Example
= Assign It assigns values from right side to left side operand. 
let a = 10;
let b = 5;
console.log("a=b:" +a);   //
Output 
10
+= Add and assign It adds the left operand with the right operand and assigns the result to the left side operand. 
let a = 10;
let b = 5;
let c = a += b;
console.log(c);   //
Output 
15
-= Subtract and assign It subtracts the right operand from the left operand and assigns the result to the left side operand. 
let a = 10;
let b = 5;
let c = a -= b;
console.log(c);   //
Output 
5
*= Multiply and assign It multiplies the left operand with the right operand and assigns the result to the left side operand. 
let a = 10;
let b = 5;
let c = a *= b;
console.log(c);   //
Output 
50
/= Divide and assign It divides the left operand with the right operand and assigns the result to the left side operand. 
let a = 10;
let b = 5;
let c = a /= b;
console.log(c);   //
Output 
2
%= Modulus and assign It divides the left operand with the right operand and assigns the result to the left side operand. 
let a = 16;
let b = 5;
let c = a %= b;
console.log(c);   //
Output 
1

三元/条件运算符

条件运算符采用三个操作数，并根据条件返回布尔值，无论该条件是true还是false。它的工作类似于if-else语句。条件运算符具有从右到左的关联性。下面给出了条件运算符的语法。

expression ? expression-1 : expression-2;
  • expression：它是指条件表达式。
  • expression-1：如果条件为true，则将返回expression-1。
  • expression-2：如果条件为假，则将返回expression-2。

例

let num = 16;
let result = (num > 0) ? "True":"False" 
console.log(result);

输出：

True

串联运算符

串联(+)运算符符是用于附加两个字符串的运算符。在串联操作中，我们不能在字符串之间添加空格。我们可以在一个语句中连接多个字符串。以下示例帮助我们理解TypeScript中的串联运算符。

例

let message = "Welcome to " + "JavaTpoint";
console.log("Result of String Operator: " +message);

输出：

Result of String Operator: Welcome to JavaTpoint

类型运算符

有可用的运算符集合，可以在使用TypeScript中的对象时为您提供帮助。类型运算符的示例包括typeof，instanceof，in和delete等运算符。这些运算符的详细说明如下。

Operator_Name Description Example
in It is used to check for the existence of a property on an object. 
let Bike = {make: 'Honda', model: 'CLIQ', year: 2018};
console.log('make' in Bike);   // 
Output:
true
delete It is used to delete the properties from the objects. 
let Bike = { Company1: 'Honda',
             Company2: 'Hero',
             Company3: 'Royal Enfield'
           };
delete Bike.Company1;
console.log(Bike);   // 
Output:
{ Company2: 'Hero', Company3: 'Royal Enfield' }
typeof It returns the data type of the operand. 
let message = "Welcome to " + "JavaTpoint";
console.log(typeof message);  // 
Output:
String
instanceof It is used to check if the object is of a specified type or not. 
let arr = [1, 2, 3];
console.log( arr instanceof Array ); // true
console.log( arr instanceof String ); // false