[Turn] console.log advanced usage

// Basic Usage

console.log ( 'The most common use of \ n newline'); 

. Console error ( 'output an error message will be displayed in red'); 

. Console The warn ( 'print a warning message will be displayed in yellow'); 

. Console info ( 'Print general information '); 

. console Clear (); // Clear display console above

 

// Advanced Usage

console.assert (false, 'determines false information was displayed'); // console.assert (bool, "info") If bool is false to print or not to print out the info 

console.table ([[ 'China', ' U.S. '], [' good ']]); // array or passed objects displayed in tabular form 

function fn () {console.trace () ;} // call chain Fn2 print () call fn1 (), fn1 () call Fn () 

function Fn1 () {Fn ();} 

function Fn2 ( ) {Fn1 ();} 

Fn2 ();

 

 // formatted output

Format flag console.log supported are:

the console.log ( 'D%% +% D = D', l, 2,3); 

// O% O% when the node is not the same print dom 
the console.log ( '% O', the document.body); 
Console .log ( '% O', the document.body); 

// behind% C content, increases css style 
@ attachment: console.log output hyperlink is automatically recognized and adding gray font color and underline style, and this can not be covered with C% 
the console.log ( 'C 456 123%', 'font-size: 36px; Color: Red;'); 
the console.log ( '123. 4% C http://www.google.com C 789% 56 is', 'font-size: 20px; Color: # ff8400;', 'font-size: 12px; Color: # 000'); 
 
// // load picture using css style not directly setting the width and height style, line-height image height, and then transferred padding 
the console.log ( '% C', 'background-image: URL ( "http://iyeslogo.orbrand.com/150902Google/005.gif"); background-size: 120% 120%; background-repeat : no-repeat; background-position: center center; line-height: 60px; padding: 30px 120px; ');

 

 // Advanced Usage

//计时，单位毫秒
    console.time();
    for(var i=0;i<100000;i++){
        var j=i*i;
    }
    console.timeEnd();
//统计代码或函数被调用了多少次
    var fn_ = function(){ console.count('hello world'); }
    for(var i=0;i<5;i++){
        fn_();
    }
//查看内存使用情况，是属性，不带括号
//console.memory;
//在浏览器开发者工具中使用
//分组输出，可嵌套
    console.group('分组1');
    console.log('语文');
    console.log('数学');
        console.group('其他科目');
        console.log('化学');
        console.log('地理');
        console.log('历史');
        console.groupEnd('其他科目');
    console.groupEnd('分组1');