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
}
}
Concat() Java Sample Output:
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
}
}
append() Java Sample Output:
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
}
}
Output:
hello world hello world JavaD