Why does console log say undefined?
log() is undefined since console. log does not explicitly return something. It has the side effect of printing to the console.,A variable declaration does not produce a value so again undefined is printed to the console.
Why does console print undefined?
8 Answers. What’s returning undefined is the statement itself that you entered into the console, NOT the value of var text.,To see that console. log(text) or simply type text in the console.,You can see content of your variable test, il will output the same thing as before.
What is the output of console log undefined ); in JavaScript?
The console will print the result of evaluating an expression. The result of evaluating console. log() is undefined since console. log does not explicitly return something.
Why are my console logs not showing?
Sounds like you’ve either hidden JavaScript logs or specified that you only want to see Errors or Warnings. Open Chrome’s Developer Tools and go to the Console tab. At the bottom you want to ensure that JavaScript is ticked and also ensure that you have “All”, “Logs” or “Debug” selected.
What does undefined in console mean?
Undefined means a variable has been declared, but the value of that variable has not yet been defined. For example: var test2;console.log(test2); // undefined. Unlike null , undefined is of the type undefined : console.log(typeof test2);
How do you fix a undefined console?
log (no debug, trace.) you can do the following:
- If console OR console. log undefined: Create dummy functions for console functions (trace, debug, log.) window.
- Else if console. log is defined (IE8) AND console. debug (any other) is not defined: redirect all logging functions to console.
Why does JavaScript show undefined?
An undefined value in JavaScript is a common occurrence— it means a variable name has been reserved, but currently no value has been assigned to that reference. It is not defined, so we call it undefined . The typeof undefined or any undeclared variable is the string “undefined” .
Why this keyword is undefined in JavaScript?
The this keyword of the clickMe arrow function refers to the global object, in this case the window object. So, this. color will be undefined because our window object does not know anything about the position or the color properties.
What can I use instead of console log?
Alternative libraries for Console. log() for your next JavaScript Project
- Console. Console is a lightweight library that can be used as an alternative to console.
- Logdown.
- Consola.
- Ololog.
- 25 CSS Best Practices you Need To Know in 2021.
What is the meaning of console log in JavaScript?
log() The console. log() method outputs a message to the web console. The message may be a single string (with optional substitution values), or it may be any one or more JavaScript objects.
What is undefined in JS?
Undefined is also a primitive value in JavaScript. A variable or an object has an undefined value when no value is assigned before using it. So you can say that undefined means lack of value or unknown value. undefined is a token.
Why does js have null and undefined?
In JavaScript, `null` and `undefined` are values and types. These are used in JavaScript to act as placeholders to let the programmer know when a variable has no value.