<!DOCTYPE html>
<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta charset="utf-8" />
<title>在100万个key里查找300个key存在情况</title>
</head>
<body>
<button class="flag-init">初始化数据(先点击一次)</button>
<button class="flag-object">Object in(可多次点击)</button>
<button class="flag-array">Array includes(可多次点击)</button>
</body>
</html>
let nr = {
tsKeyObject: {},
tsKeyArray: [],
init: (num = 1000000) => {
if (nr.tsKeyArray.length == 0) {
console.debug(`正在构建 ${num} 条数据`);
console.time();
for (let i = 0; i < num; i++) {
let item = nr.UUID();
nr.tsKeyObject[item] = true;
nr.tsKeyArray.push(item);
}
console.timeEnd();
}
},
findObject: () => {
if (nr.tsKeyArray.length) {
console.time();
let data = nr.newData();
let result = {};
data.forEach(item => {
result[item] = item in nr.tsKeyObject;
});
console.debug('find object (fast)', result)
console.timeEnd();
}
},
findArray: () => {
if (nr.tsKeyArray.length) {
console.time();
let data = nr.newData();
let result = {};
data.forEach(item => {
result[item] = nr.tsKeyArray.includes(item);
});
console.debug('find array (slow)', result)
console.timeEnd();
}
},
newData: (num = 300) => {
let data = [];
for (let i = 0; i < num; i++) {
data.push(nr.UUID());
}
return data;
},
UUID: () => window["crypto"] && window["crypto"]["randomUUID"] ? crypto.randomUUID() : URL.createObjectURL(new Blob([])).split('/').pop(),
}
document.querySelector(".flag-init").addEventListener("click", function () {
nr.init();
});
document.querySelector(".flag-object").addEventListener("click", function () {
nr.findObject();
});
document.querySelector(".flag-array").addEventListener("click", function () {
nr.findArray();
});