“Key Syntax Differences in Object-Oriented Programming: Python vs. Java”

class & object

python code:

<span>#Student is the class </span><span>class</span> <span>Student</span><span>:</span>
    <span>name</span> <span>=</span> <span>"</span><span>Momo</span><span>"</span><span>;</span>
<span>#here s1 is the object of Student class </span><span>s1</span> <span>=</span> <span>Student</span><span>()</span>   
<span>print</span><span>(</span><span>s1</span><span>.</span><span>name</span><span>)</span>
<span>#Student is the class </span><span>class</span> <span>Student</span><span>:</span>
    <span>name</span> <span>=</span> <span>"</span><span>Momo</span><span>"</span><span>;</span>

<span>#here s1 is the object of Student class </span><span>s1</span> <span>=</span> <span>Student</span><span>()</span>   
<span>print</span><span>(</span><span>s1</span><span>.</span><span>name</span><span>)</span>
#Student is the class class Student:
    name = "Momo";

#here s1 is the object of Student class s1 = Student()   
print(s1.name)

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constructor

python code

<span>class</span> <span>Student</span><span>:</span>
    <span>def</span> <span>__init__</span><span>(</span><span>self</span><span>,</span><span>fullname</span><span>):</span>  <span>#constructor </span>        <span>self</span><span>.</span><span>name</span> <span>=</span> <span>fullname</span>
<span>s1</span> <span>=</span> <span>Student</span><span>(</span><span>"</span><span>Momo</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>s1</span><span>.</span><span>name</span><span>)</span>
<span>class</span> <span>Student</span><span>:</span>

    <span>def</span> <span>__init__</span><span>(</span><span>self</span><span>,</span><span>fullname</span><span>):</span>  <span>#constructor </span>        <span>self</span><span>.</span><span>name</span> <span>=</span> <span>fullname</span>

<span>s1</span> <span>=</span> <span>Student</span><span>(</span><span>"</span><span>Momo</span><span>"</span><span>)</span>
<span>print</span><span>(</span><span>s1</span><span>.</span><span>name</span><span>)</span>
class Student:

    def __init__(self,fullname):  #constructor         self.name = fullname

s1 = Student("Momo")
print(s1.name)

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class & object in java

java code:

<span>// Student is the class</span>
<span>class</span> <span>Student</span> <span>{</span>
    <span>String</span> <span>name</span> <span>=</span> <span>"Momo"</span><span>;</span>
<span>}</span>
<span>// Main class to test the Student class</span>
<span>public</span> <span>class</span> <span>Main</span> <span>{</span>
    <span>public</span> <span>static</span> <span>void</span> <span>main</span><span>(</span><span>String</span><span>[]</span> <span>args</span><span>)</span> <span>{</span>
        <span>// s1 is the object of the Student class</span>
        <span>Student</span> <span>s1</span> <span>=</span> <span>new</span> <span>Student</span><span>();</span>
        <span>System</span><span>.</span><span>out</span><span>.</span><span>println</span><span>(</span><span>s1</span><span>.</span><span>name</span><span>);</span>
    <span>}</span>
<span>}</span>
<span>// Student is the class</span>
<span>class</span> <span>Student</span> <span>{</span>
    <span>String</span> <span>name</span> <span>=</span> <span>"Momo"</span><span>;</span>
<span>}</span>

<span>// Main class to test the Student class</span>
<span>public</span> <span>class</span> <span>Main</span> <span>{</span>
    <span>public</span> <span>static</span> <span>void</span> <span>main</span><span>(</span><span>String</span><span>[]</span> <span>args</span><span>)</span> <span>{</span>
        <span>// s1 is the object of the Student class</span>
        <span>Student</span> <span>s1</span> <span>=</span> <span>new</span> <span>Student</span><span>();</span>
        <span>System</span><span>.</span><span>out</span><span>.</span><span>println</span><span>(</span><span>s1</span><span>.</span><span>name</span><span>);</span>
    <span>}</span>
<span>}</span>
// Student is the class
class Student {
    String name = "Momo";
}

// Main class to test the Student class
public class Main {
    public static void main(String[] args) {
        // s1 is the object of the Student class
        Student s1 = new Student();
        System.out.println(s1.name);
    }
}

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constructor in java

java code:

<span>// Student class</span>
<span>class</span> <span>Student</span> <span>{</span>
    <span>String</span> <span>name</span><span>;</span> <span>// Instance variable</span>
    <span>// Constructor</span>
    <span>public</span> <span>Student</span><span>(</span><span>String</span> <span>fullname</span><span>)</span> <span>{</span>
        <span>this</span><span>.</span><span>name</span> <span>=</span> <span>fullname</span><span>;</span>
    <span>}</span>
<span>}</span>
<span>// Main class to test the Student class</span>
<span>public</span> <span>class</span> <span>Main1</span> <span>{</span>
    <span>public</span> <span>static</span> <span>void</span> <span>main</span><span>(</span><span>String</span><span>[]</span> <span>args</span><span>)</span> <span>{</span>
        <span>// Create an object of the Student class</span>
        <span>Student</span> <span>s1</span> <span>=</span> <span>new</span> <span>Student</span><span>(</span><span>"Momo"</span><span>);</span>
        <span>// Print the name</span>
        <span>System</span><span>.</span><span>out</span><span>.</span><span>println</span><span>(</span><span>s1</span><span>.</span><span>name</span><span>);</span>
    <span>}</span>
<span>}</span>
<span>// Student class</span>
<span>class</span> <span>Student</span> <span>{</span>
    <span>String</span> <span>name</span><span>;</span> <span>// Instance variable</span>

    <span>// Constructor</span>
    <span>public</span> <span>Student</span><span>(</span><span>String</span> <span>fullname</span><span>)</span> <span>{</span>
        <span>this</span><span>.</span><span>name</span> <span>=</span> <span>fullname</span><span>;</span>
    <span>}</span>
<span>}</span>

<span>// Main class to test the Student class</span>
<span>public</span> <span>class</span> <span>Main1</span> <span>{</span>
    <span>public</span> <span>static</span> <span>void</span> <span>main</span><span>(</span><span>String</span><span>[]</span> <span>args</span><span>)</span> <span>{</span>
        <span>// Create an object of the Student class</span>
        <span>Student</span> <span>s1</span> <span>=</span> <span>new</span> <span>Student</span><span>(</span><span>"Momo"</span><span>);</span>
        <span>// Print the name</span>
        <span>System</span><span>.</span><span>out</span><span>.</span><span>println</span><span>(</span><span>s1</span><span>.</span><span>name</span><span>);</span>
    <span>}</span>
<span>}</span>
// Student class
class Student {
    String name; // Instance variable

    // Constructor
    public Student(String fullname) {
        this.name = fullname;
    }
}

// Main class to test the Student class
public class Main1 {
    public static void main(String[] args) {
        // Create an object of the Student class
        Student s1 = new Student("Momo");
        // Print the name
        System.out.println(s1.name);
    }
}

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原文链接：“Key Syntax Differences in Object-Oriented Programming: Python vs. Java”