プログラミング言語比較

出力結果

2021/03/25

プログラムコード例

Go

package main 
import "fmt"
import "time"
 
func main() {
    jst, _ := time.LoadLocation("Asia/Tokyo")
    fmt.Println(time.Now().Add(-2*24*time.Hour).In(jst).Format("2006/01/02"))
}

---

JavaScript

console.log(get_x_days_ago(2));

function get_x_days_ago(x){
    var date = new Date();
    return formatDate(date.setDate(date.getDate() - x));
}

function formatDate(date) {
    var d = new Date(date),
    month = '' + (d.getMonth() + 1),
    day = '' + d.getDate(),
    year = d.getFullYear();
    if (month.length < 2)
        month = '0' + month;
    if (day.length < 2)
        day = '0' + day;
    return [year, month, day].join('/');
}

---

Perl

my ($s, $mi, $h, $d, $m, $y) = localtime(time - 2 * 24 * 60 * 60);
print sprintf("%4d/%02d/%02d", $y + 1900, $m + 1, $d)."\n";

---

PHP

<?php
echo date('Y/m/d', strtotime('2 days ago'))."\n";

---

Python

from datetime import datetime, timedelta

def get_xdays_ago(days_ago):
    x_days_ago = datetime.now() - timedelta(days=days_ago)
    return x_days_ago

print( get_xdays_ago(2).strftime("%Y/%m/%d") )

---

Ruby

require "date"
d = Date.today - 2
puts d.strftime("%Y/%m/%d")

---

Rust

Corgo.toml

[package]
name = "x_days_ago"
version = "0.0.1"

[dependencies]
chrono = "0.4"

[[bin]]
name = "x_days_ago"
path = "x_days_ago.rs"

プログラムコード

extern crate chrono;
use chrono::{Duration, Local, DateTime};

fn main() {
  let date: DateTime<Local> = Local::now() + Duration::days(-2);
  println!("{}", date.format("%Y/%m/%d"))
}

---

Shell

#/bin/sh
date -d "02/01/2000" 2>: 1>:; INVALID=$?;
if [ $INVALID == 1 ]; then
  echo `TZ=+48 date '+%Y/%m/%d'`;
else
  echo `date -d '2 days ago' '+%Y/%m/%d'`;
fi

---