#assert

In addition to logging the console object has a bunch of other useful functionality which is described below:

console.log: Just logs to the console like you would expect, corresponds to multiple levels of logging which are formatted differently across environments like browsers. Other formats:

console.debug

console.info

console.error

console.trace: Print the entire stacktrace from the current function to the top calling function. This can be useful to quickly track where a certian function is called from.

function function1() { console.trace(); } function function2() { function1(); } function2(); // Node example // Trace // at function1 (DIRECTORY/obscurejs/2018/console.js:15:11) // at function2 (DIRECTORY/obscurejs/2018/console.js:19:3) // at Object. (YOUR DIRECTORY/obscurejs/2018/console.js:21:1) // at Module._compile (module.js:652:30) // at Object.Module._extensions..js (module.js:663:10) // at Module.load (module.js:565:32) // at tryModuleLoad (module.js:505:12) // at Function.Module._load (module.js:497:3) // at Function.Module.runMain (module.js:693:10) // at startup (bootstrap_node.js:191:16)

console.assert: Throw an error when a specific value is not true which is useful to quickly debug which parts of code are not passing an expectation:

console.assert(1 + 1 === 2, '1 + 1 !== 2'); // Nothing console.assert(6 * 7 === 43, '6 * 7 !== 43'); // AssertionError [ERR_ASSERTION]: 6 * 7 !== 43 // at Console.assert (console.js:194:23) // at Object. (/Users/jacobfriesen/Documents/obscurejs/2018/console.js:37:9) // at Module._compile (module.js:652:30) // at Object.Module._extensions..js (module.js:663:10) // at Module.load (module.js:565:32) // at tryModuleLoad (module.js:505:12) // at Function.Module._load (module.js:497:3) // at Function.Module.runMain (module.js:693:10) // at startup (bootstrap_node.js:191:16) // at bootstrap_node.js:612:3

console.time: Track the time taken for a specific period by giving it a string name. Stop the check with console.timeEnd with the same string name as it was started with. Useful for quickly checking where in code there may be performance issues.

console.time('Long for loop'); for (let i = 0; i < 1e8; i += 1) {} console.timeEnd('Long for loop'); // Long for loop: 67.146ms (This will vary across runs)

console.count: Print the number of times the console.count function has been called with a string. Useful for checking the number of times a function or piece of code was entered without having to add any variables.

for (let i = 0; i < Math.round(Math.random() * 1000); i += 1) { console.count('Called loop'); } // Will print "Called loop: 15" a random number of times

There are many other console functions which can be read about here, but I never find a reason to use them frequently.

Inspiration from Sktchy http://sktchy.com/5UdOID