What will be the output of the following Java code snippet that calculates the…

Concept

A string's length is simply the total number of characters it contains — every letter, digit, space, and punctuation mark counts as exactly one character. An enhanced for-loop over str.toCharArray() visits each character once, so incrementing a counter inside the loop body produces that exact total. No characters are skipped and none are added.

Applying it to this code

The program calls customStringLength("Hello, World!"). The argument is a non-null literal, so the null guard does not fire and no exception is thrown. The loop then counts every character in turn:

1. Letters of “Hello”: H, e, l, l, o → 5 characters.

2. Punctuation and space: ',' (comma) and ' ' (space) → 2 more characters, running total 7.

3. Letters of “World”: W, o, r, l, d → 5 more, running total 12.

4. Closing punctuation: '!' → 1 more, final total 13.

So customStringLength returns 13, and the println builds the message by concatenating the literal text with this value, printing: The length of the string "Hello, World!" is: 13.

Cross-check

Counting directly by index confirms it: positions 1–13 map to H(1) e(2) l(3) l(4) o(5) ,(6) [space](7) W(8) o(9) r(10) l(11) d(12) !(13). The two halves “Hello” and “World” contribute 5 each (10), and the comma, space, and exclamation mark add 3 more, giving 13. Java's built-in "Hello, World!".length() would return the same value, which is exactly what this hand-rolled loop reproduces.