AP® Computer Science A glossary

String concatenation

Also called: concatenation

Course: AP® Computer Science A Shows up in: Unit 1: Using Objects and Methods

Joining strings with + or +=, which creates a new String. Primitives are converted to text and objects call toString.

Appears in the course and exam description (CED): 1.15.A.41.15.A.5

Java works left to right: once a String appears, + joins text. "Score: " + 4 + 5 is "Score: 45", but 4 + 5 + " pts" is "9 pts".

System.out.println("Score: " + 4 + 5);
System.out.println(4 + 5 + " pts");

Output:

Score: 45
9 pts

Related terms

• String
• Immutable
• Object class