Why doesn't the innerText of the span element changed while I use for of loop to modify the innerText?

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const colors = ["green", "red", "rgba(133,122,200)", "#f15025"];
const colorIdentifier = document.querySelector('.color');
const button = document.getElementById('btn');


for (let color of colors) {
  loopButton();
}

function loopButton() {
  button.addEventListener('click', function() {
    colorIdentifier.innerText = color;
  })
};
/* * {
  border: 5px solid purple;
} */


/*
=============== 
Fonts
===============
*/

@import url("https://fonts.googleapis.com/css?family=Open+Sans|Roboto:400,700&display=swap");

/*
=============== 
Variables
===============
*/

:root {
  /* dark shades of primary color*/
  --clr-primary-1: hsl(205, 86%, 17%);
  --clr-primary-2: hsl(205, 77%, 27%);
  --clr-primary-3: hsl(205, 72%, 37%);
  --clr-primary-4: hsl(205, 63%, 48%);
  /* primary/main color */
  --clr-primary-5: hsl(205, 78%, 60%);
  /* lighter shades of primary color */
  --clr-primary-6: hsl(205, 89%, 70%);
  --clr-primary-7: hsl(205, 90%, 76%);
  --clr-primary-8: hsl(205, 86%, 81%);
  --clr-primary-9: hsl(205, 90%, 88%);
  --clr-primary-10: hsl(205, 100%, 96%);
  /* darkest grey - used for headings */
  --clr-grey-1: hsl(209, 61%, 16%);
  --clr-grey-2: hsl(211, 39%, 23%);
  --clr-grey-3: hsl(209, 34%, 30%);
  --clr-grey-4: hsl(209, 28%, 39%);
  /* grey used for paragraphs */
  --clr-grey-5: hsl(210, 22%, 49%);
  --clr-grey-6: hsl(209, 23%, 60%);
  --clr-grey-7: hsl(211, 27%, 70%);
  --clr-grey-8: hsl(210, 31%, 80%);
  --clr-grey-9: hsl(212, 33%, 89%);
  --clr-grey-10: hsl(210, 36%, 96%);
  --clr-white: #fff;
  --clr-red-dark: hsl(360, 67%, 44%);
  --clr-red-light: hsl(360, 71%, 66%);
  --clr-green-dark: hsl(125, 67%, 44%);
  --clr-green-light: hsl(125, 71%, 66%);
  --clr-black: #222;
  --ff-primary: "Roboto", sans-serif;
  --ff-secondary: "Open Sans", sans-serif;
  --transition: all 0.3s linear;
  --spacing: 0.1rem;
  --radius: 0.25rem;
  --light-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  --dark-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  --max-width: 1170px;
  --fixed-width: 620px;
}


/*
=============== 
Global Styles
===============
*/

*,
::after,
::before {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--ff-secondary);
  background: var(--clr-grey-10);
  color: var(--clr-grey-1);
  line-height: 1.5;
  font-size: 0.875rem;
}

ul {
  list-style-type: none;
}

a {
  text-decoration: none;
}

h1,
h2,
h3,
h4 {
  letter-spacing: var(--spacing);
  text-transform: capitalize;
  line-height: 1.25;
  margin-bottom: 0.75rem;
  font-family: var(--ff-primary);
}

h1 {
  font-size: 3rem;
}

h2 {
  font-size: 2rem;
}

h3 {
  font-size: 1.25rem;
}

h4 {
  font-size: 0.875rem;
}

p {
  margin-bottom: 1.25rem;
  color: var(--clr-grey-5);
}

@media screen and (min-width: 800px) {
  h1 {
    font-size: 4rem;
  }
  h2 {
    font-size: 2.5rem;
  }
  h3 {
    font-size: 1.75rem;
  }
  h4 {
    font-size: 1rem;
  }
  body {
    font-size: 1rem;
  }
  h1,
  h2,
  h3,
  h4 {
    line-height: 1;
  }
}


/*  global classes */


/* section */

.section {
  padding: 5rem 0;
}

.section-center {
  width: 90vw;
  margin: 0 auto;
  max-width: 1170px;
}

@media screen and (min-width: 992px) {
  .section-center {
    width: 95vw;
  }
}

main {
  min-height: 100vh;
  display: grid;
  place-items: center;
}


/*
=============== 
Nav
===============
*/

nav {
  background: var(--clr-white);
  height: 3rem;
  display: grid;
  align-items: center;
  box-shadow: var(--dark-shadow);
}

.nav-center {
  width: 90vw;
  max-width: var(--fixed-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-center h4 {
  margin-bottom: 0;
  color: var(--clr-primary-5);
}

.nav-links {
  display: flex;
}

nav a {
  text-transform: capitalize;
  font-weight: 700;
  font-size: 1rem;
  color: var(--clr-primary-1);
  letter-spacing: var(--spacing);
  margin-right: 1rem;
}

nav a:hover {
  color: var(--clr-primary-5);
}


/*
=============== 
Container
===============
*/

main {
  min-height: calc(100vh - 3rem);
  display: grid;
  place-items: center;
}

.container {
  text-align: center;
}

.container h2 {
  background: var(--clr-black);
  color: var(--clr-white);
  padding: 1rem;
  border-radius: var(--radius);
  margin-bottom: 2.5rem;
}

.color {
  color: var(--clr-primary-5);
}

.btn-hero {
  font-family: var(--ff-primary);
  text-transform: uppercase;
  background: transparent;
  color: var(--clr-black);
  letter-spacing: var(--spacing);
  display: inline-block;
  font-weight: 700;
  transition: var(--transition);
  border: 2px solid var(--clr-black);
  cursor: pointer;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
  border-radius: var(--radius);
  font-size: 1rem;
  padding: 0.75rem 1.25rem;
}

.btn-hero:hover {
  color: var(--clr-white);
  background: var(--clr-black);
}
<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Color Flipper || Simple</title>

  <!-- styles -->
  <link rel="stylesheet" href="styles.css" />
</head>

<body>
  <nav>
    <div class="nav-center">
      <h4>Color Flipper</h4>
      <ul class="nav-links">
        <li><a href="index.html">simple</a></li>
        <li><a href="hex.html">hex</a></li>
      </ul>
    </div>
  </nav>

  <main>
    <div class="container">
      <h2>background color: <span class="color">#000</span></h2>
      <button class="btn btn-hero" id="btn">click me</button>
    </div>
  </main>
  <!-- javascript -->
  <script src="app.js"></script>
</body>

</html>

I want to modify the innerText of the HTML span element. And the innerText show different color of the colors array sequentially after button element got clicked.

<h2>background color: <span class="color">#000</span></h2>

I used for of loop method.

for(let color of colors) {
  loopButton();
}

function loopButton() { button.addEventListener('click', function() {
  colorIdentifier.innerText = color;
}
)};

Why is it said that "it looks like my post is mostly code even though I have used snippet?" I need to know. I think if I post a lot of code in the snippet is useful because people could see the complete code.

3 Answers

First, you get the Uncaught reference error because the event listener function is executed outside of the functional context where you added it, so it doesn't have access to the variable. An easy fix is to just pass it along:

for (const color of colors) {
    loopButton(color);
}

As for the actual looping of the colors, you're adding multiple callbacks to the same click event and element, so you're essentially overwriting them. There are several ways to accomplish what you want, but I'd suggest keeping a counter in code and incrementing it each time the button is pressed. That would make it so that the color variable has a different value every time the callback is called. Something like:

let counter = 0;
function callBack() {
    const idx = counter % (colors.length);
    colorIdentifier.innerText = colors[idx];
    colorIdentifier.style.color = colors[idx];
    counter++;
}
button.addEventListener('click', callBack);

You'll find the now-functional snippet below. Hope I've made things clearer. :)

const colors = ["green", "red", "rgba(133,122,200)", "#f15025"];
const colorIdentifier = document.querySelector('.color');
const button = document.getElementById('btn');


let counter = 0;
function callBack() {
    const idx = counter % (colors.length);
    colorIdentifier.innerText = colors[idx];
    colorIdentifier.style.color = colors[idx];
    counter++;
}
button.addEventListener('click', callBack);
/* * {
  border: 5px solid purple;
} */


/*
=============== 
Fonts
===============
*/

@import url("https://fonts.googleapis.com/css?family=Open+Sans|Roboto:400,700&display=swap");

/*
=============== 
Variables
===============
*/

:root {
  /* dark shades of primary color*/
  --clr-primary-1: hsl(205, 86%, 17%);
  --clr-primary-2: hsl(205, 77%, 27%);
  --clr-primary-3: hsl(205, 72%, 37%);
  --clr-primary-4: hsl(205, 63%, 48%);
  /* primary/main color */
  --clr-primary-5: hsl(205, 78%, 60%);
  /* lighter shades of primary color */
  --clr-primary-6: hsl(205, 89%, 70%);
  --clr-primary-7: hsl(205, 90%, 76%);
  --clr-primary-8: hsl(205, 86%, 81%);
  --clr-primary-9: hsl(205, 90%, 88%);
  --clr-primary-10: hsl(205, 100%, 96%);
  /* darkest grey - used for headings */
  --clr-grey-1: hsl(209, 61%, 16%);
  --clr-grey-2: hsl(211, 39%, 23%);
  --clr-grey-3: hsl(209, 34%, 30%);
  --clr-grey-4: hsl(209, 28%, 39%);
  /* grey used for paragraphs */
  --clr-grey-5: hsl(210, 22%, 49%);
  --clr-grey-6: hsl(209, 23%, 60%);
  --clr-grey-7: hsl(211, 27%, 70%);
  --clr-grey-8: hsl(210, 31%, 80%);
  --clr-grey-9: hsl(212, 33%, 89%);
  --clr-grey-10: hsl(210, 36%, 96%);
  --clr-white: #fff;
  --clr-red-dark: hsl(360, 67%, 44%);
  --clr-red-light: hsl(360, 71%, 66%);
  --clr-green-dark: hsl(125, 67%, 44%);
  --clr-green-light: hsl(125, 71%, 66%);
  --clr-black: #222;
  --ff-primary: "Roboto", sans-serif;
  --ff-secondary: "Open Sans", sans-serif;
  --transition: all 0.3s linear;
  --spacing: 0.1rem;
  --radius: 0.25rem;
  --light-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  --dark-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  --max-width: 1170px;
  --fixed-width: 620px;
}


/*
=============== 
Global Styles
===============
*/

*,
::after,
::before {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--ff-secondary);
  background: var(--clr-grey-10);
  color: var(--clr-grey-1);
  line-height: 1.5;
  font-size: 0.875rem;
}

ul {
  list-style-type: none;
}

a {
  text-decoration: none;
}

h1,
h2,
h3,
h4 {
  letter-spacing: var(--spacing);
  text-transform: capitalize;
  line-height: 1.25;
  margin-bottom: 0.75rem;
  font-family: var(--ff-primary);
}

h1 {
  font-size: 3rem;
}

h2 {
  font-size: 2rem;
}

h3 {
  font-size: 1.25rem;
}

h4 {
  font-size: 0.875rem;
}

p {
  margin-bottom: 1.25rem;
  color: var(--clr-grey-5);
}

@media screen and (min-width: 800px) {
  h1 {
    font-size: 4rem;
  }
  h2 {
    font-size: 2.5rem;
  }
  h3 {
    font-size: 1.75rem;
  }
  h4 {
    font-size: 1rem;
  }
  body {
    font-size: 1rem;
  }
  h1,
  h2,
  h3,
  h4 {
    line-height: 1;
  }
}


/*  global classes */


/* section */

.section {
  padding: 5rem 0;
}

.section-center {
  width: 90vw;
  margin: 0 auto;
  max-width: 1170px;
}

@media screen and (min-width: 992px) {
  .section-center {
    width: 95vw;
  }
}

main {
  min-height: 100vh;
  display: grid;
  place-items: center;
}


/*
=============== 
Nav
===============
*/

nav {
  background: var(--clr-white);
  height: 3rem;
  display: grid;
  align-items: center;
  box-shadow: var(--dark-shadow);
}

.nav-center {
  width: 90vw;
  max-width: var(--fixed-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-center h4 {
  margin-bottom: 0;
  color: var(--clr-primary-5);
}

.nav-links {
  display: flex;
}

nav a {
  text-transform: capitalize;
  font-weight: 700;
  font-size: 1rem;
  color: var(--clr-primary-1);
  letter-spacing: var(--spacing);
  margin-right: 1rem;
}

nav a:hover {
  color: var(--clr-primary-5);
}


/*
=============== 
Container
===============
*/

main {
  min-height: calc(100vh - 3rem);
  display: grid;
  place-items: center;
}

.container {
  text-align: center;
}

.container h2 {
  background: var(--clr-black);
  color: var(--clr-white);
  padding: 1rem;
  border-radius: var(--radius);
  margin-bottom: 2.5rem;
}

.color {
  color: var(--clr-primary-5);
}

.btn-hero {
  font-family: var(--ff-primary);
  text-transform: uppercase;
  background: transparent;
  color: var(--clr-black);
  letter-spacing: var(--spacing);
  display: inline-block;
  font-weight: 700;
  transition: var(--transition);
  border: 2px solid var(--clr-black);
  cursor: pointer;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
  border-radius: var(--radius);
  font-size: 1rem;
  padding: 0.75rem 1.25rem;
}

.btn-hero:hover {
  color: var(--clr-white);
  background: var(--clr-black);
}
<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Color Flipper || Simple</title>

  <!-- styles -->
  <link rel="stylesheet" href="styles.css" />
</head>

<body>
  <nav>
    <div class="nav-center">
      <h4>Color Flipper</h4>
      <ul class="nav-links">
        <li><a href="index.html">simple</a></li>
        <li><a href="hex.html">hex</a></li>
      </ul>
    </div>
  </nav>

  <main>
    <div class="container">
      <h2>background color: <span class="color">#000</span></h2>
      <button class="btn btn-hero" id="btn">click me</button>
    </div>
  </main>
  <!-- javascript -->
  <script src="app.js"></script>
</body>

</html>

Since the color is defined on another function, you can't access it, since let and const are block chained variables - They can be acces

const colors = ["green", "red", "rgba(133,122,200)", "#f15025"];
const colorIdentifier = document.querySelector('.color');
const button = document.getElementById('btn');

let i = 0;

function previewColors() {
  colorIdentifier.innerHTML = colors[i]; // Change innerHTML text
  colorIdentifier.style.color = colors[i]; // Change innerHTML color
  i++;
  if( i < colors.length){
  window.setTimeout(previewColors, 1000); // Access array after 1 sec if i < color.length - LOOPS over the array in recursive way- .
  }
}

button.addEventListener('click', previewColors);
/* * {
  border: 5px solid purple;
} */


/*
=============== 
Fonts
===============
*/

@import url("https://fonts.googleapis.com/css?family=Open+Sans|Roboto:400,700&display=swap");

/*
=============== 
Variables
===============
*/

:root {
  /* dark shades of primary color*/
  --clr-primary-1: hsl(205, 86%, 17%);
  --clr-primary-2: hsl(205, 77%, 27%);
  --clr-primary-3: hsl(205, 72%, 37%);
  --clr-primary-4: hsl(205, 63%, 48%);
  /* primary/main color */
  --clr-primary-5: hsl(205, 78%, 60%);
  /* lighter shades of primary color */
  --clr-primary-6: hsl(205, 89%, 70%);
  --clr-primary-7: hsl(205, 90%, 76%);
  --clr-primary-8: hsl(205, 86%, 81%);
  --clr-primary-9: hsl(205, 90%, 88%);
  --clr-primary-10: hsl(205, 100%, 96%);
  /* darkest grey - used for headings */
  --clr-grey-1: hsl(209, 61%, 16%);
  --clr-grey-2: hsl(211, 39%, 23%);
  --clr-grey-3: hsl(209, 34%, 30%);
  --clr-grey-4: hsl(209, 28%, 39%);
  /* grey used for paragraphs */
  --clr-grey-5: hsl(210, 22%, 49%);
  --clr-grey-6: hsl(209, 23%, 60%);
  --clr-grey-7: hsl(211, 27%, 70%);
  --clr-grey-8: hsl(210, 31%, 80%);
  --clr-grey-9: hsl(212, 33%, 89%);
  --clr-grey-10: hsl(210, 36%, 96%);
  --clr-white: #fff;
  --clr-red-dark: hsl(360, 67%, 44%);
  --clr-red-light: hsl(360, 71%, 66%);
  --clr-green-dark: hsl(125, 67%, 44%);
  --clr-green-light: hsl(125, 71%, 66%);
  --clr-black: #222;
  --ff-primary: "Roboto", sans-serif;
  --ff-secondary: "Open Sans", sans-serif;
  --transition: all 0.3s linear;
  --spacing: 0.1rem;
  --radius: 0.25rem;
  --light-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  --dark-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  --max-width: 1170px;
  --fixed-width: 620px;
}


/*
=============== 
Global Styles
===============
*/

*,
::after,
::before {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: var(--ff-secondary);
  background: var(--clr-grey-10);
  color: var(--clr-grey-1);
  line-height: 1.5;
  font-size: 0.875rem;
}

ul {
  list-style-type: none;
}

a {
  text-decoration: none;
}

h1,
h2,
h3,
h4 {
  letter-spacing: var(--spacing);
  text-transform: capitalize;
  line-height: 1.25;
  margin-bottom: 0.75rem;
  font-family: var(--ff-primary);
}

h1 {
  font-size: 3rem;
}

h2 {
  font-size: 2rem;
}

h3 {
  font-size: 1.25rem;
}

h4 {
  font-size: 0.875rem;
}

p {
  margin-bottom: 1.25rem;
  color: var(--clr-grey-5);
}

@media screen and (min-width: 800px) {
  h1 {
    font-size: 4rem;
  }
  h2 {
    font-size: 2.5rem;
  }
  h3 {
    font-size: 1.75rem;
  }
  h4 {
    font-size: 1rem;
  }
  body {
    font-size: 1rem;
  }
  h1,
  h2,
  h3,
  h4 {
    line-height: 1;
  }
}


/*  global classes */


/* section */

.section {
  padding: 5rem 0;
}

.section-center {
  width: 90vw;
  margin: 0 auto;
  max-width: 1170px;
}

@media screen and (min-width: 992px) {
  .section-center {
    width: 95vw;
  }
}

main {
  min-height: 100vh;
  display: grid;
  place-items: center;
}


/*
=============== 
Nav
===============
*/

nav {
  background: var(--clr-white);
  height: 3rem;
  display: grid;
  align-items: center;
  box-shadow: var(--dark-shadow);
}

.nav-center {
  width: 90vw;
  max-width: var(--fixed-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-center h4 {
  margin-bottom: 0;
  color: var(--clr-primary-5);
}

.nav-links {
  display: flex;
}

nav a {
  text-transform: capitalize;
  font-weight: 700;
  font-size: 1rem;
  color: var(--clr-primary-1);
  letter-spacing: var(--spacing);
  margin-right: 1rem;
}

nav a:hover {
  color: var(--clr-primary-5);
}


/*
=============== 
Container
===============
*/

main {
  min-height: calc(100vh - 3rem);
  display: grid;
  place-items: center;
}

.container {
  text-align: center;
}

.container h2 {
  background: var(--clr-black);
  color: var(--clr-white);
  padding: 1rem;
  border-radius: var(--radius);
  margin-bottom: 2.5rem;
}

.color {
  color: var(--clr-primary-5);
}

.btn-hero {
  font-family: var(--ff-primary);
  text-transform: uppercase;
  background: transparent;
  color: var(--clr-black);
  letter-spacing: var(--spacing);
  display: inline-block;
  font-weight: 700;
  transition: var(--transition);
  border: 2px solid var(--clr-black);
  cursor: pointer;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
  border-radius: var(--radius);
  font-size: 1rem;
  padding: 0.75rem 1.25rem;
}

.btn-hero:hover {
  color: var(--clr-white);
  background: var(--clr-black);
}
<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Color Flipper || Simple</title>

  <!-- styles -->
  <link rel="stylesheet" href="styles.css" />
</head>

<body>
  <nav>
    <div class="nav-center">
      <h4>Color Flipper</h4>
      <ul class="nav-links">
        <li><a href="index.html">simple</a></li>
        <li><a href="hex.html">hex</a></li>
      </ul>
    </div>
  </nav>

  <main>
    <div class="container">
      <h2>background color: <span class="color">#000</span></h2>
      <button class="btn btn-hero" id="btn">click me</button>
    </div>
  </main>
  <!-- javascript -->
  <script src="app.js"></script>
</body>

</html>

ok, is what you're trying to do is on button click to show the next color in the array? if so then this is the javascript

const colors = ["green", "red", "rgba(133,122,200)", "#f15025"]
const colorIdentifier = document.querySelector(".color")
const button = document.getElementById("btn")

// global index for so we can iterate array 1 by 1
let index = 0

// button on click event listener
button.addEventListener("click", () => {
    // set the text of colorIdentifier to colors and use the index of how many times we clicked the button
    colorIdentifier.textContent = colors[index]

    // iterate the button for on each click this is shorthand for index = index + 1
    index++

    // check to see if the index is bigger then the length and resets it back to 0
    if (index >= colors.length) index = 0
})
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