How to insert an Integer variable in a String variable in Java

Question

I need to insert an Integer variable (myLonString) in a String variable (myBufferSendTrama) in Java

Integer myLonString;
String valoOfLongOfString = Integer.toString(lonString);
myBufferSendTrama = "{\"f\":\"valoOfLongOfString\"}";     //ERROR

If the integer variable equals 20, it should look like this:

myBufferSendTrama = "{\"f\":\"20\"}";

Answer 1

You need to concatenate both strings, like:

String s1 = "jon";
String s2 = " doe";

String s3 = s1 + s2; // "jon doe"

Check out this page for more information

Answer 2

You could use String.format("{\"f\":\"%s\"}", valoOfLongOfString).

More information can be found in the docs.

Answer 3

Depending on your version of Java, you can make use of """ String literals and String.format() to achieve the effect fairly cleanly.

Example:

int value = 20;
String out = String.format("""
    Value is "%d".
    """, value);
System.out.println(out);

Output

Value is "20".

Answer 4

No need to convert the Integer to a String, just do:

Integer myLonString;
myBufferSendTrama = String.format("{\"f\":\"%d\"}",(int) myLonString);