What does + mean in js

The meaning of in JavaScript depends on the type of its operands: Number addition: Add two numbers. String concatenation: Concatenate two strings. Concatenate numbers and strings: Convert numbers to strings and then concatenate. Unary operator: adds 1 to a number. Type conversion: Convert a non-numeric value to a number. Function call: Call some function.

Meaning in js

In JavaScript, the plus sign ( ) operator has multiple meanings, specifically Depends on the type and context of its operands.

Add numbers

The most common usage is to add two numbers. For example:

<code class="js">const num1 = 10;
const num2 = 20;
const sum = num1 + num2; // sum 将等于 30</code>

String concatenation

If the plus operand is a string, it will perform string concatenation. For example:

<code class="js">const str1 = "Hello";
const str2 = "World";
const greeting = str1 + " " + str2; // greeting 将等于 "Hello World"</code>

Concatenation of numbers and strings

When one operand is a number and the other operand is a string, the number will be converted to a string, Then connect. For example:

<code class="js">const num = 123;
const str = "test";
const result = num + str; // result 将等于 "123test"</code>

Other situations

In some cases, the operator can also be used for the following operations:

• Unary Operator ( ): Increase a number by 1. For example: num increases num by 1.
• Type conversion: Force non-numeric values ​​to numbers. For example: true Converts true to the number 1.
• Function calls: Some functions can be called through the plus operator, such as Math.round().

Therefore, the meaning of in js depends on the type and context of its operands. It can be used for number addition, string concatenation, number and string concatenation, and some other specialized operations.

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