Go言語、PHP、Javaのキーワードと標準ライブラリの比較

package main

import "fmt"

func main() {
    var x int = 10
    if x > 0 {
        fmt.Println("x is positive")
    } else {
        fmt.Println("x is negative")
    }
}

<?php

$x = 10;
if ($x > 0) {
    echo "x is positive";
} else {
    echo "x is negative";
}
?>

public class Main {
    public static void main(String[] args) {
        int x = 10;
        if (x > 0) {
            System.out.println("x is positive");
        } else {
            System.out.println("x is negative");
        }
    }
}

package main

import (
    "fmt"
    "net/http"
)

func handler(w http.ResponseWriter, r *http.Request) {
    fmt.Fprintf(w, "Hello, World!")
}

func main() {
    http.HandleFunc("/", handler)
    http.ListenAndServe(":8080", nil)
}

<?php

$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

$conn = new mysqli($servername, $username, $password, $dbname);

if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}

$sql = "INSERT INTO MyGuests (firstname, lastname, email)
VALUES ('John', 'Doe', 'john@example.com')";

if ($conn->query($sql) === true) {
    echo "New record created successfully";
} else {
    echo "Error: " . $sql . "<br>" . $conn->error;
}

$conn->close();
?>

import java.util.*;

public class Main {
    public static void main(String[] args) {
        List<String> names = new ArrayList<>();
        names.add("Tom");
        names.add("Jerry");
        names.add("Alice");

        for (String name : names) {
            System.out.println(name);
        }
    }
}