How should I make js funtion run once?

Question

0.00/5 (No votes)

See more:

I need to draw a line between 2 boxes, but only once, whenever i click again, i see the line is getting thicker and thicker. I really need to execute it once cause later on I need to save it to a db, and I dont want redundant data, if it keeps saving/drawing when its executed.

var try1 = true
window.addEventListener("keydown",check,false && try1 ==true);
function check(key) {
if (key.keyCode == "65") {

c.beginPath();
c.moveTo(150,150);
c.lineTo(300,150);
c.strokeStyle ="red";
c.stroke();
try1 = false;
}}

What I have tried:

I tried whats in the link, and tried to use af for loop. I sadly didnt succeed yet!!!

Posted 11-Oct-18 0:46am

Member 14015933

Updated 11-Oct-18 0:58am

Add a Solution

1 solution

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

F-ES Sitecore · Answer 1 · 2018-10-11T00:59:00

Solution 1

Put the "try1" check in the check method

var try1 = true
window.addEventListener("keydown",check);
function check(key) {
if (try1 == true && key.keyCode == "65") {

Posted 11-Oct-18 0:59am

F-ES Sitecore

Updated 11-Oct-18 1:42am

v2

Comments

Member 14015933 11-Oct-18 7:37am

thank for your reply, but I Tried that too didnt work :/

F-ES Sitecore 11-Oct-18 7:42am

Sorry, I meant

if (try1 == true && key.keyCode == "65") {

I've updated the solution

Member 14015933 11-Oct-18 7:48am

thank you again, your comment led me to the solution, this worked so far.

var try1 = true;
window.addEventListener("keydown",check,false);
function check(key) {
if (key.keyCode == "65" && try1 == true) {

c.beginPath();
c.moveTo(150,150);
c.lineTo(300,150);
c.strokeStyle ="red"; //use hex #code

c.stroke();
try1 = false;
}