/
Upper.java
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/
Upper.java
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package com.thealgorithms.strings;
public final class Upper {
private Upper() {
}
/**
* Driver Code
*/
public static void main(String[] args) {
String[] strings = {"ABC", "ABC123", "abcABC", "abc123ABC"};
for (String s : strings) {
assert toUpperCase(s).equals(s.toUpperCase());
}
}
/**
* Converts all of the characters in this {@code String} to upper case
*
* @param s the string to convert
* @return the {@code String}, converted to uppercase.
*/
public static String toUpperCase(String s) {
if (s == null || "".equals(s)) {
return s;
}
char[] values = s.toCharArray();
for (int i = 0; i < values.length; ++i) {
if (Character.isLetter(values[i]) && Character.isLowerCase(values[i])) {
values[i] = Character.toUpperCase(values[i]);
}
}
return new String(values);
}
}