文章目录

  • 6. 控制台打印(Console)
    • 模拟Java日志打印格式
    • 美化对象打印(表格形式打印输出)
    • 日志等级输出(让其在控制台显示时有颜色提示)
    • 代码运行时间统计打印输出

6. 控制台打印(Console)

官方文档: https://developer.mozilla.org/zh-CN/docs/Web/API/Console#用法

模拟Java日志打印格式

替换字符 作用
%o 对象(可看到内部结构)
%s 字符串

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
</body>
<script>
    let people = {
        name: "lrc",
        year: 18
    }
    let article = {
        id: "423432431sfsdf",
        content: "测试控制台接口"
    }
    //不建议:这样打印不出对象内部结构
    console.log("people:" + people + " article: " + article)
    console.log("people:%s article: %s", people, article)
    //建议 == 下面两种是一样的
    console.log("people:", people, "article: ", article)
    console.log("people:%o article:%o", people, article)
</script>
</html>

前端小知识:控制台打印(console)- 模拟Java日志打印、表格形式打印美化输出对象、代码运行时间统计

美化对象打印(表格形式打印输出)

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
</body>
<script>
    let people = {
        name: "lrc",
        year: 18
    }
    let article = {
        id: "423432431sfsdf",
        content: "测试控制台接口"
    }
    console.table(people)
    console.table(article)
    let arrays = [people,article]
    console.table(arrays)
</script>
</html>

前端小知识:控制台打印(console)- 模拟Java日志打印、表格形式打印美化输出对象、代码运行时间统计

日志等级输出(让其在控制台显示时有颜色提示)

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
</body>
<script>
    console.error("错误日志哦!!!")
    console.warn("警告日志哦!!!")
    console.log("普通日志哦!!!")
</script>
</html>

前端小知识:控制台打印(console)- 模拟Java日志打印、表格形式打印美化输出对象、代码运行时间统计

代码运行时间统计打印输出

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
</body>
<script>
    console.time("代码时间统计");
    let people = {
        name: "lrc",
        year: 18
    }
    let article = {
        id: "423432431sfsdf",
        content: "测试控制台接口"
    }
    console.timeLog("代码时间统计");
    //不建议:这样打印不出对象内部结构
    console.log("people:" + people + " article: " + article)
    console.log("people:%s article: %s", people, article)
    //建议 == 下面两种是一样的
    console.log("people:", people, "article: ", article)
    console.log("people:%o article:%o", people, article)
    console.timeLog("代码时间统计");
    console.table(people)
    console.table(article)
    let arrays = [people,article]
    console.table(arrays)
    console.timeLog("代码时间统计");
    console.error("错误日志哦!!!")
    console.warn("警告日志哦!!!")
    console.log("普通日志哦!!!")
    console.timeEnd("代码时间统计");
</script>
</html>

前端小知识:控制台打印(console)- 模拟Java日志打印、表格形式打印美化输出对象、代码运行时间统计

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