Difference between concat and append in Java
Difference between concat and append in java:
In core java, its difficult to write a meaningful program without string data type. StringBuffer and StringBuilder’s are different variations of the String for different purpose in java.
But we as a java developer, needs to use concat() for string and append() for stringbuilder and stringbuffer. Knowing the difference between these two makes us a good quality developer, as this will help us to use the best one at the right use cases.
Table of Contents
concat():
- String has concat method, remember string is immutable.
- It adds a string to another string.
- It will create the new object after concatenation done, since it is a immutable.
Concat() Java Sample Program:
package com.ngdeveloper;
public class StringConcat {
public static void main(String[] args) {
//Concatenating string with another string
String helloVariable = "hello ";
String worldVariable = "world";
System.out.println(helloVariable.concat(worldVariable)); //hello world
}
}
package com.ngdeveloper;
public class StringConcat {
public static void main(String[] args) {
//Concatenating string with another string
String helloVariable = "hello ";
String worldVariable = "world";
System.out.println(helloVariable.concat(worldVariable)); //hello world
}
}
package com.ngdeveloper;
public class StringConcat {
public static void main(String[] args) {
//Concatenating string with another string
String helloVariable = "hello ";
String worldVariable = "world";
System.out.println(helloVariable.concat(worldVariable)); //hello world
}
}
Concat() Java Sample Output:
hello world
hello world
hello world
append():
- StringBuilder and StringBuffer has append method, remember these two are mutable.
- It appends a char or char sequence to a string.
- It will not create a new object, since it is a mutable one.
append() Java sample Program:
package com.ngdeveloper;
public class StringBufferBuilderAppend {
public static void main(String[] args) {
//Appending string to string
StringBuilder helloStrBuilderVariable = new StringBuilder("hello");
StringBuilder worldStrBuilderVariable = new StringBuilder(" world");
System.out.println(helloStrBuilderVariable.append(worldStrBuilderVariable)); //prints hello world
//Appending char to string
StringBuilder charVariable = new StringBuilder("Ng");
System.out.println(charVariable.append('Developer')); // prints JavaD
}
}
package com.ngdeveloper;
public class StringBufferBuilderAppend {
public static void main(String[] args) {
//Appending string to string
StringBuilder helloStrBuilderVariable = new StringBuilder("hello");
StringBuilder worldStrBuilderVariable = new StringBuilder(" world");
System.out.println(helloStrBuilderVariable.append(worldStrBuilderVariable)); //prints hello world
//Appending char to string
StringBuilder charVariable = new StringBuilder("Ng");
System.out.println(charVariable.append('Developer')); // prints JavaD
}
}
package com.ngdeveloper;
public class StringBufferBuilderAppend {
public static void main(String[] args) {
//Appending string to string
StringBuilder helloStrBuilderVariable = new StringBuilder("hello");
StringBuilder worldStrBuilderVariable = new StringBuilder(" world");
System.out.println(helloStrBuilderVariable.append(worldStrBuilderVariable)); //prints hello world
//Appending char to string
StringBuilder charVariable = new StringBuilder("Ng");
System.out.println(charVariable.append('Developer')); // prints JavaD
}
}
append() Java Sample Output:
NgDeveloper
NgDeveloper
NgDeveloper
Difference between concat and append Java Program:
package com.ngdeveloper;
public class StringConcatenation {
public static void main(String[] args) {
//Concatenating string with another string
String helloVariable = "hello ";
String worldVariable = "world";
System.out.println(helloVariable.concat(worldVariable)); //hello world
//Appending string to string
StringBuilder helloStrBuilderVariable = new StringBuilder("hello");
StringBuilder worldStrBuilderVariable = new StringBuilder(" world");
System.out.println(helloStrBuilderVariable.append(worldStrBuilderVariable)); //prints hello world
//Appending char to string
StringBuilder charVariable = new StringBuilder("Java");
System.out.println(charVariable.append('D')); // prints JavaD
}
}
package com.ngdeveloper;
public class StringConcatenation {
public static void main(String[] args) {
//Concatenating string with another string
String helloVariable = "hello ";
String worldVariable = "world";
System.out.println(helloVariable.concat(worldVariable)); //hello world
//Appending string to string
StringBuilder helloStrBuilderVariable = new StringBuilder("hello");
StringBuilder worldStrBuilderVariable = new StringBuilder(" world");
System.out.println(helloStrBuilderVariable.append(worldStrBuilderVariable)); //prints hello world
//Appending char to string
StringBuilder charVariable = new StringBuilder("Java");
System.out.println(charVariable.append('D')); // prints JavaD
}
}
package com.ngdeveloper;
public class StringConcatenation {
public static void main(String[] args) {
//Concatenating string with another string
String helloVariable = "hello ";
String worldVariable = "world";
System.out.println(helloVariable.concat(worldVariable)); //hello world
//Appending string to string
StringBuilder helloStrBuilderVariable = new StringBuilder("hello");
StringBuilder worldStrBuilderVariable = new StringBuilder(" world");
System.out.println(helloStrBuilderVariable.append(worldStrBuilderVariable)); //prints hello world
//Appending char to string
StringBuilder charVariable = new StringBuilder("Java");
System.out.println(charVariable.append('D')); // prints JavaD
}
}
Output:
hello world
hello world
JavaD
hello world
hello world
JavaD
hello world hello world JavaD
StringBuffer is synchronized as well as Thread safe so can be used in multithreading. StringBuilder is not synchronized as well as thread safe. Many thanks for sharing this.