console.log

Does console.log invokes toString method of an object?

由 北战南征 提交于 2019-11-26 11:28:40
问题 As per this documentation, The string representations of each of these objects are appended together in the order listed and output. Also as per answer The + x coerces the object x into a string, which is just [object Object]: So, my question is If I do str = new String(\"hello\") console.log(str) //prints the string object but not \'hello\' console.log(\"\"+str) //prints \"hello\" So, in first case, it simply prints the object (doesn\'t invoke the toString() method). But in second case, it

Node.js: printing to console without a trailing newline?

由 拥有回忆 提交于 2019-11-26 07:50:33
问题 Is there a method for printing to the console without a trailing newline? The console object documentation doesn\'t say anything regarding that: console.log() Prints to stdout with newline. This function can take multiple arguments in a printf() -like way. Example: console.log(\'count: %d\', count); If formating elements are not found in the first string then util.inspect is used on each argument. 回答1: You can use process.stdout.write() : process.stdout.write("hello: "); See the docs for

JavaScript console.log causes error: “Synchronous XMLHttpRequest on the main thread is deprecated…”

由 我只是一个虾纸丫 提交于 2019-11-26 05:41:01
问题 I have been adding logs to the console to check the status of different variables without using the Firefox debugger. However, in many places in which I add a console.log in my main.js file, I receive the following error instead of my lovely little handwritten messages to myself: Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user\'s experience. For more help http://xhr.spec.whatwg.org/ What alternatives to or wrappers for console.log

Why is console.log() considered better than alert()?

由 徘徊边缘 提交于 2019-11-26 05:25:51
I've always been told that when debugging an application, JavaScript's console.log() method is preferred over simply using an alert() method. Why is this? Is there a good example someone can point me to where console.log() is obviously the better choice? alert() is blocking alert() cannot be easily suppressed in non-debug environment console typically formats your objects nicely and allows to traverse them logging statements often have an interactive pointer to code which issued logging statement you cannot look at more than one alert() message at a time console s can have different logging

Google Chrome console.log() inconsistency with objects and arrays

由 不打扰是莪最后的温柔 提交于 2019-11-26 03:22:08
问题 I was helping a colleague debug some code today and I noticed a strange behavior with console.log() in Google Chrome: It appears that if you: Create a nested array (e.g., [[345,\"test\"]]) Log the array to the console with console.log() . Modify one of the inner array values, then console.log() will output the later value -- not the values of the array at the time the console.log() was executed. JavaScript : var test = [[2345235345,\"test\"]] console.log(test); test[0][0] = 1111111; //

Why is console.log() considered better than alert()?

由 余生长醉 提交于 2019-11-26 01:54:53
问题 I\'ve always been told that when debugging an application, JavaScript\'s console.log() method is preferred over simply using an alert() method. Why is this? Is there a good example someone can point me to where console.log() is obviously the better choice? 回答1: alert() is blocking alert() cannot be easily suppressed in non-debug environment console typically formats your objects nicely and allows to traverse them logging statements often have an interactive pointer to code which issued

Can't access object property, even though it shows up in a console log

由 ℡╲_俬逩灬. 提交于 2019-11-26 01:28:01
问题 Below, you can see the output from these two logs. The first clearly shows the full object with the property I\'m trying to access, but on the very next line of code, I can\'t access it with config.col_id_3 (see the \"undefined\" in the screenshot?). Can anyone explain this? I can get access to every other property except field_id_4 as well. console.log(config); console.log(config.col_id_3); This is what these lines print in Console 回答1: The output of console.log(anObject) is misleading; the

What is console.log?

由 半城伤御伤魂 提交于 2019-11-26 01:20:01
问题 What is the use of console.log ? Please explain how to use it in JavaScript, with a code example. 回答1: It's not a jQuery feature but a feature for debugging purposes. You can for instance log something to the console when something happens. For instance: $('#someButton').click(function() { console.log('#someButton was clicked'); // do something }); You'd then see #someButton was clicked in Firebug’s “Console” tab (or another tool’s console — e.g. Chrome’s Web Inspector) when you would click

JavaScript - Owner of “this”

由 穿精又带淫゛_ 提交于 2019-11-26 00:38:43
问题 I followed a tutorial for creating a JavaScript stopwatch and am trying to expand it to work with multiple stopwatches (multiple instances of a class). The problem I have is when I am trying to display the current value while the clock is ticking I need to hard code the class instance becasue using \"this\" doesn\'t work (on the line where I am using console.log). I have cut the code down to the minimum to try to understand this aspect, and have pasted what I have below: function Timer(){ var

How can I get the full object in Node.js's console.log(), rather than '[Object]'?

由 笑着哭i 提交于 2019-11-26 00:08:00
问题 When debugging using console.log() , how can I get the full object? const myObject = { \"a\":\"a\", \"b\":{ \"c\":\"c\", \"d\":{ \"e\":\"e\", \"f\":{ \"g\":\"g\", \"h\":{ \"i\":\"i\" } } } } }; console.log(myObject); Outputs: { a: \'a\', b: { c: \'c\', d: { e: \'e\', f: [Object] } } } But I want to also see the content of property f . 回答1: You need to use util.inspect() : const util = require('util') console.log(util.inspect(myObject, {showHidden: false, depth: null})) // alternative shortcut
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