if(document.querySelectorAll("img")){
     [...document.querySelectorAll("img")].forEach(elm=>{
        fetch(elm.src).then(response=>{
            if(!response.ok){
                elm.src = "no_image1.gif";
            }
        });
     });
}

counterHtml = "<br><span id='counter'>アクセスカウンター：0</span><br><br>";
document.getElementById("site_description").insertAdjacentHTML("afterend",counterHtml);
if(!(localStorage.getItem("counter")) || ( parseInt(localStorage.getItem("counter")) + 420000 < (new Date()).getTime()) ){
    fetch("/counter/?counter=1").then(response=>response.json()).then(data=>{
        document.getElementById("counter").innerText = "アクセスカウンター：" + data.cnt;
        localStorage.setItem("counter",(new Date()).getTime());
    });
}else{
    fetch("/counter/?counter=0").then(response=>response.json()).then(data=>{
        document.getElementById("counter").innerText = "アクセスカウンター：" + data.cnt;
        localStorage.setItem("counter",(new Date()).getTime());
    });
}

<?php
if($_GET["counter"]==1){
    $cnt = (int)(file_get_contents("cnt.txt"));
    $cnt++;
    file_put_contents("cnt.txt",$cnt);
    print json_encode(["cnt"=>$cnt]);
}else{
    print json_encode(["cnt"=>(int)file_get_contents("cnt.txt")]);
}

document.getElementById('btn').addEventListener('click', () => {
    const formData = new FormData();
    formData.append('id', document.getElementById('id_number').value);
    formData.append('_method','PUT');//DELETE・PATCH・PUT

    fetch('ajax-test', {
        method: 'POST',
        headers: {'X-CSRF-TOKEN': document.querySelector('meta[name="csrf-token"]').content}, // CSRFトークン対策
        body: formData
    })
        .then(response => response.json()) 
        .then(res => {
            console.log('res: '+res[0].id);
            document.getElementById("result").innerHTML = "ID番号" + res[0].id + "は「" + res[0].name + "」です。価格は「" + res[0].price+"円」です。";
        })
        .catch(error => {
            console.log(error); // エラー表示
        });
});

"use strict";
var csv = {
	load:async function(filename,id){
		const responseFile = await fetch(filename);
        const result = await responseFile.text()
		let separate1 = /\r\n/;
		let separate2 = ",";
		let data = (result.split(separate1)).map(function(value){
			return (value.split(separate2)).map(function(value1){
				return value1;
			});
		});
		let sum =[];
		for (const usedata of data) {
            (usedata).map(function(val,index,array){
                sum[index] = (isNaN(parseInt(sum[index]))?0:parseInt(sum[index])) + parseInt(array[index]);
            });
		}
        console.log(sum);
		document.getElementById(id).innerHTML = sum.join(",");
		return "OK";
	}
};
csv.load("math.csv?", "sum");

var ken_json = {};
fetch("./assets/js/ken47.json").then(response => response.json()).then((data)=>{
	let ken = [];
	for (const key in data) {
		ken.push("<a href='#' onClick='c19(\"" + "https://hazard.yahoo.co.jp/article/covid19" + data[key].roman +"\")' onmouseover='c19_f(\"" + data[key].roman.toUpperCase() + "\",\"red\")'' onmouseout='c19_f(\"" + data[key].roman.toUpperCase() + "\",\"#fff\")'>" + data[key].name + "</a>");
	}
	document.getElementById("covid19-link-list").innerHTML = ken.join(",");
	for (const key in data) {
		document.getElementById(data[key].roman.toUpperCase()).setAttribute("fill","#fff");
	}
});

function c19(url){
	window.open(url,"_blank");
}
function c19_f(kenid,color){
	document.getElementById(kenid).setAttribute("fill",color);
}	

{
	"1": {
		"name": "北海道",
		"roman": "hokkaido"
	},
	"2": {
		"name": "青森",
		"roman": "aomori"
	},
	"3": {
		"name": "岩手",
		"roman": "iwate"
	},
	"4": {
		"name": "宮城",
		"roman": "miyagi"
	},
	"5": {
		"name": "秋田",
		"roman": "akita"
	},
	"6": {
		"name": "山形",
		"roman": "yamagata"
	},
	"7": {
		"name": "福島",
		"roman": "fukushima"
	},
	"8": {
		"name": "茨城",
		"roman": "ibaraki"
	},
	"9": {
		"name": "栃木",
		"roman": "tochigi"
	},
	"10": {
		"name": "群馬",
		"roman": "gunma"
	},
	"11": {
		"name": "埼玉",
		"roman": "saitama"
	},
	"12": {
		"name": "千葉",
		"roman": "chiba"
	},
	"13": {
		"name": "東京",
		"roman": "tokyo"
	},
	"14": {
		"name": "神奈川",
		"roman": "kanagawa"
	},
	"15": {
		"name": "新潟",
		"roman": "niigata"
	},
	"16": {
		"name": "富山",
		"roman": "toyama"
	},
	"17": {
		"name": "石川",
		"roman": "ishikawa"
	},
	"18": {
		"name": "福井",
		"roman": "fukui"
	},
	"19": {
		"name": "山梨",
		"roman": "yamanashi"
	},
	"20": {
		"name": "長野",
		"roman": "nagano"
	},
	"21": {
		"name": "岐阜",
		"roman": "gifu"
	},
	"22": {
		"name": "静岡",
		"roman": "shizuoka"
	},
	"23": {
		"name": "愛知",
		"roman": "aichi"
	},
	"24": {
		"name": "三重",
		"roman": "mie"
	},
	"25": {
		"name": "滋賀",
		"roman": "shiga"
	},
	"26": {
		"name": "京都",
		"roman": "kyoto"
	},
	"27": {
		"name": "大阪",
		"roman": "osaka"
	},
	"28": {
		"name": "兵庫",
		"roman": "hyogo"
	},
	"29": {
		"name": "奈良",
		"roman": "nara"
	},
	"30": {
		"name": "和歌山",
		"roman": "wakayama"
	},
	"31": {
		"name": "鳥取",
		"roman": "tottori"
	},
	"32": {
		"name": "島根",
		"roman": "shimane"
	},
	"33": {
		"name": "岡山",
		"roman": "okayama"
	},
	"34": {
		"name": "広島",
		"roman": "hiroshima"
	},
	"35": {
		"name": "山口",
		"roman": "yamaguchi"
	},
	"36": {
		"name": "徳島",
		"roman": "tokushima"
	},
	"37": {
		"name": "香川",
		"roman": "kagawa"
	},
	"38": {
		"name": "愛媛",
		"roman": "ehime"
	},
	"39": {
		"name": "高知",
		"roman": "kochi"
	},
	"40": {
		"name": "福岡",
		"roman": "fukuoka"
	},
	"41": {
		"name": "佐賀",
		"roman": "saga"
	},
	"42": {
		"name": "長崎",
		"roman": "nagasaki"
	},
	"43": {
		"name": "熊本",
		"roman": "kumamoto"
	},
	"44": {
		"name": "大分",
		"roman": "oita"
	},
	"45": {
		"name": "宮崎",
		"roman": "miyazaki"
	},
	"46": {
		"name": "鹿児島",
		"roman": "kagoshima"
	},
	"47": {
		"name": "沖縄",
		"roman": "okinawa"
	}
}

<script>
	fetch("./assets/js/ken47.json").then(response => response.json()).then((data)=>{
		let ken = [];
		ken.push('<div class="list-group">');
		for (const key in data) {
			ken.push("<a  class='list-group-item list-group-item-action' href='https://hazard.yahoo.co.jp/article/covid19" + data[key].roman + "' target='_"+ data[key].roman +"'>" + data[key].name +":::https://hazard.yahoo.co.jp/article/covid19" + data[key].roman + "</a>");
		}
		ken.push("</div>");
		document.getElementById("covid19-link-list").innerHTML = ken.join("")
	});
</script>

{
	"1": {
		"name": "北海道",
		"roman": "hokkaido"
	},
	"2": {
		"name": "青森",
		"roman": "aomori"
	},
	"3": {
		"name": "岩手",
		"roman": "iwate"
	},
	"4": {
		"name": "宮城",
		"roman": "miyagi"
	},
	"5": {
		"name": "秋田",
		"roman": "akita"
	},
	"6": {
		"name": "山形",
		"roman": "yamagata"
	},
	"7": {
		"name": "福島",
		"roman": "fukushima"
	},
	"8": {
		"name": "茨城",
		"roman": "ibaraki"
	},
	"9": {
		"name": "栃木",
		"roman": "tochigi"
	},
	"10": {
		"name": "群馬",
		"roman": "gunma"
	},
	"11": {
		"name": "埼玉",
		"roman": "saitama"
	},
	"12": {
		"name": "千葉",
		"roman": "chiba"
	},
	"13": {
		"name": "東京",
		"roman": "tokyo"
	},
	"14": {
		"name": "神奈川",
		"roman": "kanagawa"
	},
	"15": {
		"name": "新潟",
		"roman": "niigata"
	},
	"16": {
		"name": "富山",
		"roman": "toyama"
	},
	"17": {
		"name": "石川",
		"roman": "ishikawa"
	},
	"18": {
		"name": "福井",
		"roman": "fukui"
	},
	"19": {
		"name": "山梨",
		"roman": "yamanashi"
	},
	"20": {
		"name": "長野",
		"roman": "nagano"
	},
	"21": {
		"name": "岐阜",
		"roman": "gifu"
	},
	"22": {
		"name": "静岡",
		"roman": "shizuoka"
	},
	"23": {
		"name": "愛知",
		"roman": "aichi"
	},
	"24": {
		"name": "三重",
		"roman": "mie"
	},
	"25": {
		"name": "滋賀",
		"roman": "shiga"
	},
	"26": {
		"name": "京都",
		"roman": "kyoto"
	},
	"27": {
		"name": "大阪",
		"roman": "osaka"
	},
	"28": {
		"name": "兵庫",
		"roman": "hyogo"
	},
	"29": {
		"name": "奈良",
		"roman": "nara"
	},
	"30": {
		"name": "和歌山",
		"roman": "wakayama"
	},
	"31": {
		"name": "鳥取",
		"roman": "tottori"
	},
	"32": {
		"name": "島根",
		"roman": "shimane"
	},
	"33": {
		"name": "岡山",
		"roman": "okayama"
	},
	"34": {
		"name": "広島",
		"roman": "hiroshima"
	},
	"35": {
		"name": "山口",
		"roman": "yamaguchi"
	},
	"36": {
		"name": "徳島",
		"roman": "tokushima"
	},
	"37": {
		"name": "香川",
		"roman": "kagawa"
	},
	"38": {
		"name": "愛媛",
		"roman": "ehime"
	},
	"39": {
		"name": "高知",
		"roman": "kochi"
	},
	"40": {
		"name": "福岡",
		"roman": "fukuoka"
	},
	"41": {
		"name": "佐賀",
		"roman": "saga"
	},
	"42": {
		"name": "長崎",
		"roman": "nagasaki"
	},
	"43": {
		"name": "熊本",
		"roman": "kumamoto"
	},
	"44": {
		"name": "大分",
		"roman": "oita"
	},
	"45": {
		"name": "宮崎",
		"roman": "miyazaki"
	},
	"46": {
		"name": "鹿児島",
		"roman": "kagoshima"
	},
	"47": {
		"name": "沖縄",
		"roman": "okinawa"
	}
}