Color code your console log messages with a shorter syntax to console.log and easily turn off console logging by setting a DEV_MODE variable to false.

devmode-console-helper.js

/*

	Author: 	Josh McDonald
	Twitter:	@onestepcreative
	Website:	joshmcdonald.net


	A simple helper to log color coded messages to the
	javascript console, using a shorter syntax to console.log 
	You can leave your dev.log() statements scattered throughout
	your code, and easily turn off logging for production
	by setting the global DEV_MODE variable to false;
	
	To activate these tools:
	DEV_MODE = true;

	Simple helper methods:
	dev.mode()			- check to see if tools are available
	dev.check()			- quickly check the state of a boolean value

	Available console methods:
	dev.log()			- your default console.log statement
	dev.info()			- logs bright blue text	
	dev.warn()			- logs bright orange text
	dev.error()			- logs bright red text
	dev.start()			- logs bright green text
	dev.end()			- logs bright red text

	Just for shorter syntax:
	dev.group()			- nested block of console statements
	dev.groupEnd()		- closes most recently opened group
	dev.profile()		- turns on the js profiler
	dev.profileEnd()	- turns off the js profiler
	
	// To see example usage
	dev.sample()

*/



DEV_MODE = true;



window.dev = {

    log: function(msg, obj) {
        
        msg = (arguments.length === 2) ? msg + ': ' : msg;
        
        obj = (obj) ? obj : '';
        
        if(dev.enabled()) {
    		
    		if(typeof msg !== 'string') {
    		 
    			console.log('%c ' + 'data: ', 'font-family:"Helvetica Neue", Helevetica; font-size:13px;', msg);
    		
    		} else {
    		
    			console.log('%c ' + msg, 'font-family:"Helvetica Neue", Helevetica; font-size:13px;', obj);
    			
    		}
    		
    	}
        
    },

    info: function(msg, obj) {
        
        obj = (obj) ? obj : '';
        
    	if(dev.enabled()) {
    		
    		if(typeof msg !== 'string') {
    		 
    			console.log('%c ' + 'data: ', 'color: #00F; font-family:"Helvetica Neue", Helevetica; font-size:13px;', msg);
    		
    		} else {
    		
    			console.log('%c ' + msg, 'color: #00F; font-family:"Helvetica Neue", Helevetica; font-size:13px;', obj);
    			
    		}
    		
    	}    
        
    },
    
    warn: function(msg, obj) {
        
        obj = (obj) ? obj : '';
        
    	if(dev.enabled()) {
    		
    		if(typeof msg !== 'string') {
    		 
    			console.log('%c ' + 'data: ', 'color: #FFA500; font-family:"Helvetica Neue", Helevetica; font-size:13px;', msg);
    		
    		} else {
    		
				console.log('%c ' + msg, 'color: #FFA500; font-family:"Helvetica Neue", Helevetica; font-size:13px;', obj);    
        
			}
			
		}
        
    },
    
    error: function(msg, obj) { 
    	
    	obj = (obj) ? obj : '';
    	
    	if(dev.enabled()) {
    		
    		if(typeof msg !== 'string') {
    		 
    			console.log('%c ' + 'data: ', 'color: Orangered; font-family:"Helvetica Neue", Helevetica; font-size:13px;', msg);
    		
    		} else {
    		
				console.log('%c ' + msg, 'color: Orangered; font-family:"Helvetica Neue", Helevetica; font-size:13px;', obj);    
        
			}
			
		}
    	
    },
    
    start: function(msg, obj) {
        
        obj = (obj) ? obj : '';
        
        if(dev.enabled()) {
    		
    		if(typeof msg !== 'string') {
    		 
    			console.log('%c ' + 'data start: ', 'color: #0F0; font-family:"Helvetica Neue", Helevetica; font-size:13px; font-weight:bold;', msg);
    		
    		} else {
    		
				console.log('%c ' + msg, 'color: #0F0; font-family:"Helvetica Neue", Helevetica; font-size:13px; font-weight:bold;', obj);    
        
			}
			
		}
                
    },
    
    end: function(msg, obj) {
        
        obj = (obj) ? obj : '';
        
        if(dev.enabled()) {
    		
    		if(typeof msg !== 'string') {
    		 
    			console.log('%c ' + 'data end: ', 'color: #F00; font-family:"Helvetica Neue", Helevetica; font-size:13px; font-weight:bold;', msg);
    		
    		} else {
    		
				console.log('%c ' + msg, 'color: #F00; font-family:"Helvetica Neue", Helevetica; font-size:13px; font-weight:bold;', obj);    
        
			}
			
		}
        
    },
    
    group: function(title) {
        
        obj = (obj) ? obj : '';
        
    	if(dev.enabled()) console.group(title);    
        
    },
    
    groupEnd: function() {
        
        obj = (obj) ? obj : '';
        
    	if(dev.enabled()) console.groupEnd();    
        
    },
    
    profile: function(title) {
        
    	if(dev.enabled()) {
    	
    		(title) ? console.profile(title) : console.profile();
    		
    	}    
        
    },
    
    profileEnd: function(title) {
        
    	if(dev.enabled()) {
	    	
	    	(title) ? console.profileEnd('End Profile: ' + title) : console.profileEnd('End Profile');	
	    	
    	}    
        
    },
    
    check: function(state, msg) {
	    
		if(dev.enabled()) console.log('%c ' + state + ':', 'color: Fuchsia; font-weight:bold', msg);
	    
    },
    
	mode: function(msg) {
	
		if(dev.enabled()) {
	
			console.log('%c DEV MODE IS ON', 'color: #0F0; font-weight:bold');
	
		} else {
	
			console.log('%c DEV MODE IS OFF', 'color: #F00; font-weight:bold');
	
		}
	
	},
	
	sample: function() {
		
		// Run dev.sample() to print examples to console 
		
		var sampleObj = { id: 234567, msg: 'testing message', myobj: { id: '4567', msg: 'obj testing message' } };
	
		dev.log('regular console message');
		dev.info('this is an info statement');
		dev.warn('this is a warning statement');
		dev.error('this is an error statement');
		dev.start('starting something');
		dev.end('ending something');
		
		dev.log('regular with data', sampleObj);
		dev.info('info with data', sampleObj);
		dev.warn('warn with data', sampleObj);
		dev.error('error with data', sampleObj);
		dev.start('start with data', sampleObj);
		dev.end('end with data', sampleObj);
		
		dev.log(sampleObj);
		dev.info(sampleObj);
		dev.warn(sampleObj);
		dev.error(sampleObj);
		dev.start(sampleObj);
		dev.end(sampleObj);	
		
	},

    enabled: function() { return (window.console && DEV_MODE) ? true : false; }
    
};