JSON | modify an array value of a JSON object

The arrays in JSON (JavaScript Object Notation) are similar to arrays in Javascript. Arrays in JSON can have values of following types:

  • null
  • boolean
  • number
  • string
  • array
  • object

The arrays in JavaScript can have all these but it can also have other valid JavaScript expressions which are not allowed in JSON.

Array value of a JSON object can be modified. It can be simply done by modifying the value present at a given index.

Example: Modifying the value present at an index in array

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<!DOCTYPE html>
<html>
<body>
<p id = "GFG">< /p>
  
<script>
  
var myObj, i, x = "";
myObj = {
      
    // stored the values
    "words":[ "I", "am", "Good" ]
};
  
// modifying the value present at index 2
myObj.words[2] = "bad"
  
for (i in myObj.words) {
  
    // Displaying the modified content
    x += myObj.words[i] + "<br>"
}
  
document.getElementById("GFG").innerHTML = x;
  
</script>
</body>
</html>                    

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Output :

I
am
bad

Note: If value is modified at an index which is out of the array size, then the new modification will not replace anything in the original information but rather will be an add-on.

Example: Modifying the value of index which is out of the array size.

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<!DOCTYPE html>
<html>
<body>
<p id = "GFG"></p>
  
<script>
  
var myObj, i, x = "";
myObj = {
      
    // stored values
    "words":[ "I", "am", "Good"
};
  
// trying to change a value at
// an index out of array size
myObj.words[3] = "bad"
  
for (i in myObj.words) { 
  
    // display the modification
    x += myObj.words[i] + "<br>";
}
  
document.getElementById("GFG").innerHTML = x;
  
</script>
</body>
</html>                    

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Output :

I
am
Good
bad


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