The role of the plus sign in js

The functions of the plus sign ( ) in JavaScript include: numerical addition, string connection variables and string connection, implicit type conversion, positive unary operation

The role of the plus sign in JavaScript

The plus sign ( ) symbol in JavaScript has multiple roles, depending on what it operates on.

1. Numerical addition:

If the operation object is two or more numerical values, the plus sign is used to perform numerical addition operations. For example:

<code class="javascript">const sum = 1 + 2 + 3; // sum 为 6</code>

2. String concatenation:

If the operation object is two or more strings, the plus sign is used to perform string concatenation operations. For example:

<code class="javascript">const greeting = "Hello" + " " + "World"; // greeting 为 "Hello World"</code>

3. Variable and string concatenation:

If the operation object is a string and a variable, the plus sign converts the variable to a string, and perform string concatenation. For example:

<code class="javascript">const name = "John";
const message = "Welcome, " + name; // message 为 "Welcome, John"</code>

4. Implicit type conversion:

If the data types of the operation objects are different, the plus sign can perform implicit type conversion. For example:

<code class="javascript">const result = 1 + "2"; // result 为 "12" (字符串)</code>

In this example, the value 1 is implicitly converted to a string in order to be concatenated with the string "2".

5. Unary operator:

The plus sign can also be used as a unary operator to convert a number to its positive number. For example:

<code class="javascript">const positiveNumber = +(-10); // positiveNumber 为 10</code>

Note:

• If the operands are Boolean values, the plus sign will perform an implicit type conversion, converting them to numeric values.
• The plus sign has low priority, lower than multiplication and division operations.

The above is the detailed content of The role of the plus sign in js. For more information, please follow other related articles on the PHP Chinese website!