[Flutter] How to Reverse String in Dart: Efficient String Reversal Techniques in Dart

By splitting the input string str into an array of individual characters, then reversing the order of the characters in the array, and finally joining them back together into a single string.

// Function: firstReverse
// Input: str (a string)
// Output: a reversed version of the input string
// Description: This function takes a string as input and returns a reversed version of that string.
String firstReverse(String str) {
// Split the input string into an array of characters,
// reverse the array, and then join the characters back into a string.
return str.split('').reversed.join('');
}


By iterating over the characters of the input string in reverse order and appending each character to a new string revString. Finally, it returns the reversed string.

String firstReverse(String str) {
// Initialize an empty string to store the reversed string
String revString = '';

// Iterate over the characters of the input string in reverse order
// starting from the last character (index: str.length - 1) to the first character (index: 0)
for (int index = str.length - 1; index >= 0; index--) {
// Append each character to the 'revString'
revString += str[index];
}

// Return the reversed string
return revString;
}


Reverse String with the help of StringBuffer The first method utilizes Dart's StringBuffer class to efficiently construct the reversed string by appending characters in reverse order. This method is straightforward and efficient for reversing strings.

String firstReverse(String str) {
StringBuffer reverseString = StringBuffer();

for (int index = str.length-1; index >= 0; index--) {
reverseString.write(str[index]);
}

return reverseString.toString();
}


Reverse String with the help of CodeUnit: The second method converts each character of the input string into its Unicode code point using codeUnitAt, stores them in a list, reverses the list in-place, and then converts the Unicode code points back into characters using String.fromCharCode

String firstReverse(String str) {
var stringToNumList = [];
String reverseStr = '';

for (var i = 0; i < str.length; i++) {
stringToNumList.add(str.codeUnitAt(0));
}

int start = 0, last = stringToNumList.length - 1;

while (start < last) {
var temp = stringToNumList[start];
stringToNumList[start] = stringToNumList[last];
stringToNumList[last] = temp;
start++;
last--;
}

for (var i = 0; i < stringToNumList.length; i++) {
reverseStr += String.fromCharCode(stringToNumList);
}

return reverseStr;
}

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