Articles tagged "Java value passing"

Java Method Parameter Passing: Pass by Value or Pass by Reference? A Comprehensive Guide

2025-12-20 78 views Java syntax Java value passing Java method parameter passing Value passing vs reference passing Java Reference Type Passing Java Fundamentals Tutorial

In Java, the essence of method parameter passing is **pass-by-value**, not pass-by-reference. Beginners often misunderstand it as "pass-by-reference" due to the behavior of objects with reference types, which is actually a confusion of concepts. Pass-by-value means the method receives a "copy" of the parameter; modifying the copy does not affect the original variable. Pass-by-reference, by contrast, transfers the "reference address," and modifications will affect the original object. In Java, all parameter passing is the former: - **Primitive types** (e.g., `int`): A copy of the value is passed. For example, in the `swap` method, modifying the copy does not affect the original variables (as demonstrated, the `swap` method cannot exchange `x` and `y`). - **Reference types** (e.g., objects, arrays): A copy of the reference address is passed. Although the copy and the original reference point to the same object, modifying the object's properties will affect the original object (e.g., changing the `name` attribute of a `Student` object). However, modifying the reference itself (to point to a new object) will not affect the original object (e.g., the `changeReference` method in the example does not alter the original object). Core conclusion: Java only has "pass-by-value." The special behavior of reference types arises from "shared access to the object via a copied reference address," not from the passing method being "pass-by-reference."

Introduction to Java Methods: Definition, Invocation, and Parameter Passing – Get It After Reading

2025-12-20 105 views Java syntax Introduction to Java Methods Java Method Definition Java method invocation Java parameter passing Java value passing

This article introduces the basic knowledge of Java methods, including definition, invocation, and parameter passing. A method is a tool for encapsulating repeated code, which can improve reusability. Definition format: `Modifier ReturnType MethodName(ParameterList) { MethodBody; return ReturnValue; }`. Examples include a parameterless and returnless `printHello()` method (to print information) and a parameterized and returnable `add(int a, int b)` method (to calculate the sum of two numbers). Invocation methods: Static methods can be directly called using `ClassName.MethodName(ActualParameters)`, while non-static methods require an object. For example, `printHello()` or `add(3,5)`. Parameter passing: Basic types use "pass-by-value", where modifications to formal parameters do not affect actual parameters. For instance, in `changeNum(x)`, modifying the formal parameter `num` will not change the value of the original variable `x`. Summary: Methods enhance code reusability. Mastering definition, invocation, and pass-by-value is the core. (Note: The full text is approximately 280 words, covering core concepts and examples to concisely explain the key points for Java method beginners.)