To convert a string to lowercase and uppercase, we can use the built-in methods of the JavaScript string class like toLowerCase() and toUpperCase(). Additionally, we can split the string in half using the string length property or the substring() method.
We will learn two methods in this tutorial to convert half of a string to uppercase and the other half to lowercase using JavaScript.
Use for loop, toUpperCase() and toLowerCase() methods
We can use a for loop to get half a string. Afterwards, we can convert the first half of the string to uppercase using the toUpperCase() method. After that, we need to convert the second half of the string to lowercase using the toLowerCase() method.
grammar
Users can use the toUpperCase() and toLowerCase() methods according to the following syntax to convert the first half of the string to uppercase and the other part to lowercase.
for (let k = 0; k < length / 2; k++) {
newStr += string[k].toUpperCase();
}
for (k = length / 2; k < length; k++) {
newStr += string[k].toLowerCase();
}
In the above syntax, length is the string length and we convert the specific characters of the string to upper and lower case.
algorithm
Step 1 - Use the length property of the string and get the string length.
Step 2 - Create a newStr variable and initialize it with an empty string to store the newly converted string.
Step 3 - Use a for loop to iterate the first half. Also, convert each character in the first half to uppercase and append it to the newStr string variable.
Step 4 - Now, use a for loop to iterate over the other half of the string and convert each character to lowercase using the toLowerCase() method. Also, append lowercase characters to the newStr variable.
Step 5 - The newStr variable contains the converted string.
Example 1
In the following example, we create a string containing some characters. After that, we use the above algorithm to convert the first half of the string to uppercase and the other half to lowercase.
In the output, the user can observe the converted string.
<html>
<body>
<h2 id="Using-the-i-for-loop-toUpperCase-and-toLowerCase-i-methods">Using the <i> for-loop, toUpperCase(), and toLowerCase() </i> methods </h2>
<h3 id="Converting-first-half-of-the-string-in-uppercase-and-another-half-in-lowercase">Converting first half of the string in uppercase and another half in lowercase</h3>
<div id = "output"> </div>
<script>
let output = document.getElementById('output');
let string = "fdSDksndsMSDSAXS";
let length = string.length;
let newStr = "";
for (let k = 0; k < length / 2; k++) {
newStr += string[k].toUpperCase();
}
for (k = length / 2; k < length; k++) {
newStr += string[k].toLowerCase();
}
output.innerHTML += "The original string is " + string + "<br/>";
output.innerHTML += "The converted string is " + newStr + "<br/>";
</script>
</body>
</html>
step
Step 1 - Get the length of the string in the length variable.
Step 2 - Create firstHalf and secondHalf variables and initialize them with empty string.
Step 3 - Now, use a for-of loop to iterate over each string character. Additionally, on each iteration, append a character to the firstHalf string variable and check the value of the k variable. If it is greater than length/2, break the loop.
Step 4 - Now, use the for-of loop again to iterate the second half and perform the same operations as the first half.
Step 5 - Next, convert firstHalf to uppercase and secondHalf to lowercase. After that, merge the two strings using the " " operator.
Example 2
In the example below, the first for-of loop finds the first half of the string, and the other for-of loop finds the second half of the string. We also show the firstHalf and secondHalf variable values using the converted strings in the output.
<html>
<body>
<h2 id="Using-the-i-for-of-loop-toUpperCase-and-toLowerCase-i-methods-to-convert-first-half-of-the-string-in-uppercase-and-another-half-in-lowercase">Using the <i>for-of loop, toUpperCase(), and toLowerCase()</i> methods to convert first half of the string in uppercase and another half in lowercase.</h2>
<div id = "output"> </div>
<script>
let output = document.getElementById('output');
let originalString = "fsfJKkjkUYFERSDFXwaZAsawecas";
let length = originalString.length;
let firstHalf = "";
let secondHalf = "";
let k = 0;
for (let char of originalString) {
if (k < length / 2) {
firstHalf += char
k++;
} else {
break;
}
}
k=0;
for (let char of originalString) {
if (k>= length/2 && k < length) {
secondHalf += char
}
k++;
}
let convertedStr = firstHalf.toUpperCase() + secondHalf.toLowerCase();
output.innerHTML += "The original string is " + originalString + "<br/>";
output.innerHTML += "The first half of the string is " + firstHalf + "<br/>";
output.innerHTML += "The second half of the string is " + secondHalf + "<br/>";
output.innerHTML += "The converted string is " + convertedStr + "<br/>";
</script>
</body>
</html>
Use substr(), toUpperCase() and toLowerCase() methods
The substr() method allows us to get a substring from the original string. In this method, we will get the first half substring and the second half substring using substr() method.
grammar
Users can use the substr(), toUpperCase() and toLowerCase() methods according to the following syntax to convert the first half to uppercase and the other part to lowercase.
let convertedStr = stringToConvert.substr(0, length / 2).toUpperCase() + stringToConvert.substr(length / 2).toLowerCase();
In the above syntax, we use the substr() method twice to get the first half of the string and the other half of the string.
algorithm
Step 1 - Get the length of the string.
Step 2 - Use the substr() method to get the first half. The user needs to pass in 0 as the first parameter, which represents the starting point, and length/2 as the second parameter, which represents the length of the substring.
Step 3 - Use the substr() method again to get the other half. Pass length/2 as the first argument to get the substring from length/2 to the end.
Example 3
In the following example, we use the substr() method to get both halves of the substring and use the toUpperCase() method for the first half and the toLowerCase() method for the second half.
<html>
<body>
<h2 id="Using-the-i-substr-toUpperCase-and-toLowerCase-i-methods-to-convert-first-half-of-the-string-in-uppercase-and-another-half-in-lowercase">Using the <i> substr(), toUpperCase(), and toLowerCase() </i> methods to convert first half of the string in uppercase and another half in lowercase.</h2>
<div id = "output"> </div>
<script>
let output = document.getElementById('output');
let stringToConvert = "erteDCSRDEWdEREre4ere";
let length = stringToConvert.length;
let convertedStr = stringToConvert.substr(0, length / 2).toUpperCase() + stringToConvert.substr(length / 2).toLowerCase();
output.innerHTML += "The original string is " + stringToConvert + "<br/>";
output.innerHTML += "The converted string is " + convertedStr + "<br/>";
</script>
</body>
</html>
Users learned to use a for loop and the substr() method to convert the first half of a string to uppercase and the other half to lowercase. Using the substr() method, we need to write one line of code to achieve our goal. Therefore, this is the recommended approach.
The above is the detailed content of How to create a string that is half uppercase and half lowercase?. For more information, please follow other related articles on the PHP Chinese website!
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