What is the difference between Java functions and JavaScript functions?

The difference between Java and JavaScript functions is: Syntax: Java functions are declared with public static void main(String[] args) { }, while JavaScript functions are declared with function main() { }. Type: Java is a strongly typed language, and each variable has a specified data type, while JavaScript is a weakly typed language, and the variable type is determined at runtime. Parameter passing: Java passes parameters by value, while JavaScript passes objects by reference. Return value: Java functions can explicitly return a value or return no value, whereas JavaScript functions always return a value, even if the value is undefined.

The difference between Java functions and JavaScript functions

Introduction

Java and JavaScript Despite their similar names, they are very different languages. As object-oriented and object-based languages, they also have significant differences in the definition and syntax of functions. This article will delve into the main differences between Java functions and JavaScript functions and provide a practical example to understand these differences.

Syntax

• Java function declaration:

  public static void main(String[] args) {
    // 函数体
  }

• JavaScript function declaration:

  function main() {
    // 函数体
  }

Type

• Java functions are strongly typed languages ​​and types are enforced at compile time examine. Each variable or parameter has a specified data type.
• JavaScript functions are weakly typed languages, and the types of variables and parameters are determined at runtime.

Parameter passing

• Java functions pass parameters by value, which means the original value of the parameter is copied into the function.
• JavaScript functions pass objects by reference, which means that any modifications to the parameters will be reflected in the original object that called the function.

Return value

• Java functions can explicitly return a value or not return any value (void).
• JavaScript functions always return a value, even if the value is undefined.

Practical case

Java function:

public static int sum(int a, int b) {
    return a + b;
}

JavaScript function:

function sum(a, b) {
    return a + b;
}

Run the case:

// Java
System.out.println(sum(10, 20)); // 输出 30

// JavaScript
console.log(sum(10, 20)); // 输出 30

In this case, both the Java function and the JavaScript function output 30. However, please note that if you modify the value of a within a JavaScript function, it will affect the original object on which the function was called. In contrast, in Java, modifications to a do not affect the original object.

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