String manipulation in Kotlin involves manipulating and performing operations on strings. Kotlin provides numerous built-in functions and methods to easily perform string manipulation tasks. Here are some common string operations in Kotlin:
- Concatenation: To combine two or more strings, you can use the + operator or the plus() method. For example, val fullName = firstName + " " + lastName or val fullName = firstName.plus(" ").plus(lastName).
- Length: To find the length of a string, you can use the length property. For example, val strLength = str.length.
- Substring: To extract a portion of a string, you can use the substring() function. It takes the starting and ending index as arguments. For example, val subStr = str.substring(2, 5).
- Replace: To replace part of a string with another value, you can use the replace() function. It takes the old value and new value as arguments. For example, val newStr = str.replace("old", "new").
- Split: To split a string into an array of substrings based on a delimiter, you can use the split() function. It takes the delimiter as an argument. For example, val strArray = str.split(",").
- Trim: To remove leading and trailing white spaces from a string, you can use the trim() function. For example, val trimmedStr = str.trim().
- Convert to Upper/Lower Case: To convert a string to lowercase or uppercase, you can use the toLowerCase() or toUpperCase() functions respectively. For example, val lowerStr = str.toLowerCase() or val upperStr = str.toUpperCase().
- Check if Starts/Ends With: To check if a string starts or ends with a specific prefix or suffix, you can use the startsWith() or endsWith() functions respectively. For example, val startsWithFoo = str.startsWith("foo") or val endsWithBar = str.endsWith("bar").
These are just a few examples of string manipulation operations in Kotlin. Kotlin provides many more powerful functions and extensions to work with strings efficiently.
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What is the difference between equals() and equalsIgnoreCase() for string comparison in Kotlin?
In Kotlin, both equals() and equalsIgnoreCase() are methods used for string comparison, but they have different functionalities:
- equals(): This method compares two strings based on both their content and case sensitivity. It returns true if the strings are exactly the same, including the case of the characters. For example:
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val str1 = "Hello" val str2 = "hello" println(str1.equals(str2)) // prints false |
- equalsIgnoreCase(): This method compares two strings based on their content while ignoring the case sensitivity. It returns true if the strings are the same, regardless of the case of the characters. For example:
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val str1 = "Hello" val str2 = "hello" println(str1.equalsIgnoreCase(str2)) // prints true |
In summary, the equals() method checks for an exact match with case sensitivity, while equalsIgnoreCase() checks for a match while ignoring case sensitivity.
How to convert a string to a float in Kotlin?
To convert a string to a float in Kotlin, you can use the toFloat() function. Here's an example:
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fun main() { val str = "3.14" val floatValue = str.toFloat() println(floatValue) } |
Output:
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3.14
|
In this example, the toFloat() function is called on the string str to convert it into a floating-point value.
How to convert a string to a list of characters in Kotlin?
To convert a string to a list of characters in Kotlin, you can use the toList() function.
Here's an example:
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fun main() { val str = "Hello, World!" val charList = str.toList() println(charList) // [H, e, l, l, o, ,, , W, o, r, l, d, !] } |
In this example, the toList() function is called on the string str, which converts it to a list of characters charList. The resulting list contains each character from the string as a separate element.
