What is the procedure for renaming an item within a basic array in Angular?

Question

What is the procedure for renaming an item within a basic array in Angular?

I am working on a project in Angular and have constructed an array.
I am now looking to change the name of one of the items in this array. While I have figured out how to rename keys in an array, I'm still unsure about how to do so for its values.

Below is the array I am referring to.
I want to replace 'valueC' with 'valueZ'.

myArray = ['valueA', 'valueB', 'valueC']

I attempted the following code :

    for (const k in this.myArray) {
        if (k == "valueC") {
            this.myArray[k] = "valueZ";
        }

Unfortunately, it did not work as expected.

Could someone please assist me with this issue?
I would greatly appreciate any help, thank you.

javascript arrays angular typescript

Answer 1

Answer №1

Discover two different techniques below!

const myArray = ['valueA', 'valueB', 'valueC']

//modify - known index
myArray[2] = 'valueZ';
console.log('if index known', myArray);

//modify - unknown index
const foundIndex = myArray.findIndex(x => x === 'valueC');
if (foundIndex > -1) {
  myArray[2] = 'valueZ';
}
console.log('if index not known', myArray);

Answer 2

Discover two different techniques below!

const myArray = ['valueA', 'valueB', 'valueC']

//modify - known index
myArray[2] = 'valueZ';
console.log('if index known', myArray);

//modify - unknown index
const foundIndex = myArray.findIndex(x => x === 'valueC');
if (foundIndex > -1) {
  myArray[2] = 'valueZ';
}
console.log('if index not known', myArray);

Answer 3

Answer №2

A slight adjustment is all that's needed in your code:

 if (this.myArray[k] == "valueC")

Answer 4

A slight adjustment is all that's needed in your code:

 if (this.myArray[k] == "valueC")

Answer 5

Answer №3

Give this a shot:

let sampleArray = ['apple', 'banana', 'cherry'];
for (const key in sampleArray) {
  if (sampleArray[key] === "cherry") {
    sampleArray[key] = "orange";
  }
} 
console.log(sampleArray);

Answer 6

Give this a shot:

let sampleArray = ['apple', 'banana', 'cherry'];
for (const key in sampleArray) {
  if (sampleArray[key] === "cherry") {
    sampleArray[key] = "orange";
  }
} 
console.log(sampleArray);

Answer 7

Answer №4

To keep track of the index, a forEach loop is recommended

this.myArray.forEach((item, index) => {
   if (item == "valueC") {
     this.myArray[index] = "valueZ";
   }
})

My preferred method: However, ensure that the value "valueC" is present in the array otherwise indexOf will return -1, causing an error

// without index check
this.myArray[this.myArray.indexOf("valueC")] = "valueZ";

// with index check
const index = this.myArray.indexOf("valueC")
if (index >= 0) {
  this.myArray[index] = "valueZ";
}

Remember this for future reference :)

for (const item in array) : in this scenario, item represents the index of elements in the array
for (const item of array) : in this case, item represents the value of elements in the array

Answer 8

To keep track of the index, a forEach loop is recommended

this.myArray.forEach((item, index) => {
   if (item == "valueC") {
     this.myArray[index] = "valueZ";
   }
})

My preferred method: However, ensure that the value "valueC" is present in the array otherwise indexOf will return -1, causing an error

// without index check
this.myArray[this.myArray.indexOf("valueC")] = "valueZ";

// with index check
const index = this.myArray.indexOf("valueC")
if (index >= 0) {
  this.myArray[index] = "valueZ";
}

Remember this for future reference :)

for (const item in array) : in this scenario, item represents the index of elements in the array
for (const item of array) : in this case, item represents the value of elements in the array

Answer 9

Answer №5

In addition to the other solutions provided, I recommend another method that promotes immutability by returning a new object instead of altering the existing one.

For example:

this.myArray = this.myArray.map(x => {
    if(x !== 'valueC')
        return x;

    return 'valueZ';
});

Using map in this way creates a new array object, specifically a string array based on your current array being a string array. This approach focuses on only handling the negative case, where values are not 'valueC' and remain unchanged while 'valueC' gets replaced with 'valueZ'.

Answer 10

In addition to the other solutions provided, I recommend another method that promotes immutability by returning a new object instead of altering the existing one.

For example:

this.myArray = this.myArray.map(x => {
    if(x !== 'valueC')
        return x;

    return 'valueZ';
});

Using map in this way creates a new array object, specifically a string array based on your current array being a string array. This approach focuses on only handling the negative case, where values are not 'valueC' and remain unchanged while 'valueC' gets replaced with 'valueZ'.

What is the procedure for renaming an item within a basic array in Angular?

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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