js 关于console对象

// js console
console.clear();
console.log("console.log,show message, last recommand is console.clear");
console.info("console.info,other name for console.log");
console.warn("console.warn");
console.error("console.error");
console.assert(1 === 2, "console.assert,if first argument is false show me");
console.log(
  "%clast is console.count which can show how many console.count was been used",
  "color:green"
);
console.count("console.count used num");
console.count("console.count used num");
console.group("console.group:this is first group");
console.group("this is second group");
console.log("this is console.log which in console.group");
console.log(
  "every console.group need a console.groupEnd at bottom,eg. here need two"
);
console.groupEnd();
console.groupEnd();
console.groupCollapsed(
  "the same to console.group,this is collapsed default which is defferent to console.group"
);
console.log("this need end too,use console.groupEnd too");
console.groupEnd();
console.log(
  "%cnext is console.table which can show complexed data such as arr or obj in table",
  "color:green"
);
console.table(["arr1", "arr2", "arr3"]);
// console.table([['arr1','arr2','arr3'],['a1','a2','a3']])
// console.table({'firstkey':'firstvalue','secondkey':'secondval'})
console.log(
  "%cnext is console.time which can count how many time the program used in it,certainly it need a console.timeEnd at the program end",
  "color:green"
);
console.time();
for (var i = 0; i < 1000; i++) {}
console.timeEnd();
console.log(
  "%chere not show how to use console.trace which can show the process of a program which included console.trace",
  "color:green"
);
console.warn("this is console.warn");
console.log(
  "%console.profile,sorry to tell you i do not understant either",
  "color:green"
);
console.log(
  "%cconsole.log can use some placeholder such as %s,%d or %i,%f,%o,%O,%c,\n (\\n)those can replace string,integer,float,dom,dom attr,css style such as this green message and next some console.log",
  "color:green"
);
console.log('%cred fontsize 20px','color:red;font-size:20px')
console.log("%d年%d月%d日",2011,3,26);
// console.log('%o',document.body.firstElementChild);
// console.log('%O',document.body.firstElementChild);
console.log("%chere show background-img and the website i referenced","background:url(https://static.runoob.com/images/runoob-logo.png) no-repeat;padding:10px;line-height:40px;color:red;padding-left:300px;font-size:15px");

 运行出来：