Java add string
last modified January 27, 2024
Java add string tutorial shows how to concatenate strings in Java.
In Java, a string is a sequence of Unicode characters. Strings are objects. There are two basic classes for working with strings:
There are several ways how to add strings in C#:
- + operator
- concat method
- String.join method
- StringBuilder append method
- String.format
Java add strings with + operator
The easiest way of concatenating strings is to use the + or the
+= operator. The + operator is used both for adding numbers and
strings; in programming we say that the operator is overloaded.
package com.zetcode;
public class AddStrings {
public static void main(String[] args) {
System.out.println("Return" + " of " + "the king.");
String msg = "There are";
msg += " three";
msg += " falcons";
msg += " in the sky";
System.out.println(msg);
}
}
The example adds two strings using the + and +=
operators.
$ java com/zetcode/AddStrings.java Return of the king. There are three falcons in the sky
Java add strings with String.concat
The String.concat method concatenates the specified string to the
end of this string.
package com.zetcode;
public class AddStrings {
public static void main(String[] args) {
System.out.println("Return".concat(" of ").concat("the king."));
}
}
In the example, we add strings with String.concat.
Java add strings with String.join
The String.join method returns a new atring composed of copies of
the CharSequence elements joined together with a copy of the specified
delimiter.
package com.zetcode;
public class AddStrings {
public static void main(String[] args) {
String[] words = { "There", "are", "two", "owls", "on", "the", "tree" };
String msg = String.join(" ", words);
System.out.println(msg);
}
}
We have an array of words. We form a sentence from the words with the
String.join method.
$ java com/zetcode/AddStrings.java There are two owls on the tree
Java add strings with StringBuilder
StringBuilder is a mutable sequence of characters. Its append method appends the specified string to the string instance.
package com.zetcode;
public class AddStrings {
public static void main(String[] args) {
var sb = new StringBuilder();
sb.append("Return");
sb.append(" of ");
sb.append("the king.");
System.out.println(sb);
}
}
In the example, we form a new string with StringBuilder.
$ java com/zetcode/AddStrings.java Return of the king.
Java add strings with String.format
The String.format method returns a formatted string using the
specified format string and arguments.
package com.zetcode;
public class AddStrings {
public static void main(String[] args) {
var w1 = "three";
var w2 = "owls";
var msg = String.format("There are %s %s on the tree", w1, w2);
System.out.println(msg);
}
}
In the example, we build a new string with String.format.
Source
Java String - language reference
In this article we have showed how to add strings in Java.
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