nentokake urutan ngendi statement dieksekusi. Java nyediake kondisional (, ), loop (, , ), lan statement percabangan (, , ) — plus peningkatan modern kaya switch expression.
ifswitchforwhiledo-whilebreakcontinuereturnif (score >= 90) {
grade = "A";
} else if (score >= 80) {
grade = "B";
} else {
grade = "F";
}
// ternary — concise if/else for a value
String status = (age >= 18) ? "adult" : "minor";
switch (day) {
case 1: name = "Mon"; break; // ⚠️ break needed — else it FALLS THROUGH
case 2: name = "Tue"; break;
default: name = "Unknown";
}
Switch klasik mbutuhake break sawise saben case — lali bakal nyebabake fall-through (eksekusi terus menyang case sabanjure), minangka sumber bug sing kondhang.
// arrow syntax: no fall-through, returns a value, more concise
String name = switch (day) {
case 1 -> "Mon";
case 2 -> "Tue";
case 6, 7 -> "Weekend"; // multiple labels
default -> "Unknown";
};
Switch expression modern ngilangake fall-through, bisa ngasilake nilai, lan luwih resik — disenengi ing kode anyar.
// for — known iteration count
for (int i = 0; i < 10; i++) { ... }
// enhanced for-each — iterate a collection/array
for (String item : items) { ... }
// while — condition checked BEFORE each iteration
while (condition) { ... }
// do-while — body runs at least ONCE (condition checked after)
do { ... } while (condition);
for (int i = 0; i < 10; i++) {
if (i == 5) break; // exit the loop entirely
if (i % 2 == 0) continue; // skip to the next iteration
}
return result; // exit the method
// labeled break — exit nested loops
outer:
for (...) {
for (...) {
if (found) break outer; // breaks BOTH loops
}
}
break metu saka loop, continue lompat menyang iterasi sabanjure, return metu saka method, lan break sing dilabel bisa metu saka nested loop bebarengan.
Aliran kontrol minangka mekanisme dhasar kanggo nglaksanakake logika lan keputusan ing program apa wae — saben method sing ora mbrengos nggunake.
Pahami konstruksi lan nuansa-nuansane penting: gotcha fall-through switch (lan switch expression modern sing luwih aman), bedane while lan do-while (jalankan minimal sapisan), for-each kanggo iterasi koleksi sing bersih, lan statement percabangan (kasamben break sing dilabel kanggo nested loop).
Menguasai iki — lan pilih bentuk modern sing luwih ora entuk kesalahan (switch expression, for-each) — dadi penting kanggo nulis logika Java sing bener lan bisa dibaca lan ninggalake bug aliran kontrol sing umum.