// 干支の計算方法は？
// 十二支は、西暦を１２で割り、同様に余りを求めます。 
let eto = ['申', '酉', '戌', '亥', '子', '丑', '寅', '卯', '辰', '巳', '午', '未'];
document.querySelector('.input').addEventListener('input', function () {
    let index = isNaN(Number(document.querySelector('.input').value)) ? -1 : (Number(document.querySelector('.input').value) % 12);
    document.querySelector('#res').innerText = index === -1 ? '' : eto[index];
});

<button id="likeBtn">👍</button>
<button id="dislikeBtn">👎</button>

<p><span id="likeCount">0</span></p>

// カウンターの初期値を設定
let likeCount = 0;
let dislikeCount = 0;

// 「いいね」ボタンのクリックイベントを追加
document.getElementById("likeBtn").addEventListener("click", function() {
  likeCount++;
  document.getElementById("likeCount").textContent = likeCount;
});

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
        });
});

let funs = {
    init: { htmlcode: document.getElementById("vals").innerHTML },
    highlight: function (e) {
        document.getElementById("vals").innerHTML = funs.init.htmlcode;
        if (!String(this.value).match(/[a-zA-Z]/) && this.value) {
            document.getElementById("vals").innerHTML = String(funs.init.htmlcode).replace(new RegExp(this.value, 'g'), '<span style="color:red">' + this.value + '</span>');
        }
    },
    inputevent:function(){
        document.getElementById("txt").addEventListener("input", this.highlight);
    }
};
funs.inputevent();

let circle = document.getElementById("circle");
document.body.addEventListener("mousemove",function(e){
    let a = e.currentTarget.getBoundingClientRect();
    let x = e.clientX - a.left;
    let y = e.clientY - a.top; 
    circle.style.top = `${y}px`;
    circle.style.left = `${x}px`;
    circle.style.transform = `translate(50px,50px)`;
})

document.querySelector(".btn").addEventListener("click", () => {
    let p = [document.querySelector("[name='name']").value, document.querySelector("[name='text']").value];
    [...document.querySelectorAll(".put")].forEach((elm, index) => {
        elm.innerText = p[index];
    });
    document.querySelector("#box2").style.display = "none";
    document.querySelector("#data").insertAdjacentHTML("beforeend", `<button class="btn2" type="button">非同期送信</button>`);
    document.querySelector(".btn2").addEventListener("click", async () => {
        //submit code
        let url = "./submit.php";
        let data = (() => {
            return ([...document.querySelectorAll(".put")].map((elm, index) => {
                return "test" + index + "=" + elm.innerText;
            })).join("&");
        })();
        const options = {
            method: 'POST',
            headers: {
                'Content-Type': 'application/x-www-form-urlencoded',
                "Content-Length": data.length,
                'Accept': 'application/json'
            },
            body: data //JSON.stringify(data)
        };
        await fetch(url, options).then(response =>
            response.json()
        ).then(resultdata => {
            document.getElementById("view").insertAdjacentHTML("beforeend", resultdata.test0 + "," + resultdata.test1);
        }).catch(error => {
            console.log(error);
        });
    });
});


function imgchg(imagename){
    document.body.setAttribute("style","background-image: url(./assets/images/" + imagename + ".jpg");
}

document.getElementById("sh").addEventListener("input",(e)=>{
    $.ajax({
        type: "post",
        url: "example.com/sh.php",
        data: {text:this.value},
        dataType: "json",
        success: function (response) {
            
        }
    });
});

    <form id="frm" method="post" action="./example/">
        <input type="hidden" name="example" value="data">
        <button type="submit" class="btn btn-primary">Submit1</button>
    </form>
    <form method="post" action="./example/">
        <input type="hidden" name="example" value="data">
        <button id="btn" type="submit" class="btn btn-primary">Submit2</button>
    </form>    
    <form method="post" action="./example/" onsubmit="return func1()" >
        <input type="hidden" name="example" value="data">
        <button type="submit" class="btn btn-primary">Submit3</button>
    </form>
    <form method="post" action="./example/"  >
        <input type="hidden" name="example" value="data">
        <button type="submit" class="btn btn-primary" onclick="return func2()" >Submit4</button>
    </form>

//例１
document.getElementById("frm").addEventListener("submit",function(event){
    event.preventDefault();
});
//例２
document.getElementById("btn").addEventListener("click",function(event){
    event.preventDefault();
    event.stopPropagation();//インターフェイスのメソッドで、キャプチャおよびバブリング段階において現在のイベントのさらなる伝播を阻止します。 
});
//例３
function func1(){
    return false;
}
//例４
function func2(){
    return false;
}

document.getElementById("example").addEventListener("input",function(){
    main()
})
document.getElementById("example").addEventListener("input",main);

function main(){
    if(this.value){
        console.log(this);
    }
}

document.getElementById("btn").addEventListener("click", async (e) => {
	test1();
	test2();
	test3();
	await test1();
	await test2();
	await test3();
});

function test1() {
	return new Promise(resolve => {
		setTimeout(() => {
			console.log("btn = 1");
			resolve('1');
		}, 3000);
	});
}
function test2() {
	return new Promise(resolve => {
		setTimeout(() => {
			console.log("btn = 2");
			resolve('2');
		}, 2000);
	});
}
async function test3() {
	return new Promise(resolve => {
		setTimeout(() => {
			console.log("btn = 3");
			resolve('3');
		}, 100);
	});
}

<script src="./assets/js/common.js"></script>

<script type="text/javascript" src="./assets/js/common.js"></script>

document.getElementById("btn").addEventListener("click", async (e) => {
	test1();
	test2();
	test3();
	await test1();
	await test2();
	await test3();
});

function test1() {
	return new Promise(resolve => {
		setTimeout(() => {
			console.log("btn = 1");
			resolve('1');
		}, 3000);
	});
}
function test2() {
	return new Promise(resolve => {
		setTimeout(() => {
			console.log("btn = 2");
			resolve('2');
		}, 2000);
	});
}
async function test3() {
	return new Promise(resolve => {
		setTimeout(() => {
			console.log("btn = 3");
			resolve('3');
		}, 100);
	});
}

	const test = (e)=>{
		var view = document.querySelector("#view1");
		view.innerHTML = e.target.value;
	};
	const input = document.querySelector("#t");
	input.addEventListener("input",test);