Java Community | Help. Code. Learn.•8mo ago

Week 68 — Which mechanisms does Java provide for concatenating `String`s with other variables?

Question of the Week #68

Which mechanisms does Java provide for concatenating Strings with other variables?

11 Replies

String concatenation is the mechanism of combining a String with another variable in order to get another String containing both the original String and the other variable. Java allows doing that using the + operator:

String s = "Hello ";
String t = "World ";
int i = 1337;
String result = s + t + i;
System.out.println(result);//Hello World 1337

String s = "Hello ";
String t = "World ";
int i = 1337;
String result = s + t + i;
System.out.println(result);//Hello World 1337

Other than that, the String class provides a concat method that can concatenate two Strings:

String s = "Hello ";
String t = "World";
String result = s.concat(t);
System.out.println(result);//Hello World

String s = "Hello ";
String t = "World";
String result = s.concat(t);
System.out.println(result);//Hello World

It is also possible to use String.format which allows printf-like format specifiers:

String s = "Hello";
String t = "World";
int i = 1337;
String result = String.format("%s %s %d", s, t, i);
System.out.println(result);//Hello World 1337

String s = "Hello";
String t = "World";
int i = 1337;
String result = String.format("%s %s %d", s, t, i);
System.out.println(result);//Hello World 1337

Aside from that, String templates, which are currently (as of Java 22) a Preview feature, allow doing that as well:

String s = "Hello";
String t = "World";
int i = 1337;
String result = STR."\{s} \{t} \{i}";
System.out.println(result);//Hello World 1337

String s = "Hello";
String t = "World";
int i = 1337;
String result = STR."\{s} \{t} \{i}";
System.out.println(result);//Hello World 1337

📖 Sample answer from dan1st

Eric McIntyre•8mo ago

Java provides + operator to concatenate the string with other variables Like int a = 3; String str = "times"; System.out.print(a+str); // 3times We can also use stringbuilder for optimised concatenation as strings are immutable in java for larger string we use stringbuilder

Submission from rahulsaini_1957

Eric McIntyre•8mo ago

Usually you can concatenate with

 String + var1

 String + var1

Submission from ogbudsz

Eric McIntyre•8mo ago

For concatenation of string with other variables addition "+" mechanism is provided by java

Submission from dead_pool4

Eric McIntyre•8mo ago

The use of the ‘+’ operator allows the concatenation of various data types to string types. For example str = “Hello” and x = 1 str + x = Hello1 Using the StringBuilder class and using .append() has the same effect though StringBuilder has more methods to use

Submission from _draws

Eric McIntyre•8mo ago

For example StringBuilder Or method .concat for string object In the worst case "s += i" or s = "s + i"

Eric McIntyre•8mo ago

I'll give code example later if needed

Submission from matieuu

Eric McIntyre•8mo ago

In java we can use an empty string Eg: class hi{ void hello{ String a=“hi” String B=“world” String c=a+B}}

Eric McIntyre•8mo ago

@JavaBot

Submission from juanisrockingx

Eric McIntyre•8mo ago

1. We can use '+' operator.

String name = "Cutie";
int age = 25;
String message = "Hello, my name is " + name + " and I am " + age + " years old.";
System.out.println(message);

String name = "Cutie";
int age = 25;
String message = "Hello, my name is " + name + " and I am " + age + " years old.";
System.out.println(message);

2. Also String.format() is available.

String name = "Cutie";
int age = 25;
String message = "Hello, my name is %s, and I am %d years old.";
System.out.println(message);

String name = "Cutie";
int age = 25;
String message = "Hello, my name is %s, and I am %d years old.";
System.out.println(message);

3. StringBuilder is another option.

String name = "Cutie";
int age = 25;
StringBuilder builder = new StringBuilder();
builder.append("Hello, my name is ").append(name).append(" and I am ").append(age).append(" years old.");
String message = builder.toString();
System.out.println(message);

String name = "Cutie";
int age = 25;
StringBuilder builder = new StringBuilder();
builder.append("Hello, my name is ").append(name).append(" and I am ").append(age).append(" years old.");
String message = builder.toString();
System.out.println(message);

⭐ Submission from cutie.joy

Eric McIntyre•8mo ago

** Possible answer: 1) + operator is used to concatenate two strings. 2) StringBuilder also gives us the capability to concatenate strings and other variables. ** 1) Code: String s1 = "java "; String s2 = "week"; System.out.println(s1 + s2); Output: -> java week * 2) Code String str = "java week "; int a = 1; StringBuilder stb = new StringBuilder(); stb.append(str); stb.append(a); System.out.println(stb.toString()); Output: -> java week 1

⭐ Submission from sk001

Gaming

Programming

Week 68 — Which mechanisms does Java provide for concatenating `String`s with other variables?