文字列

NSString *

String

ミュータブル配列

NSMutableArray *	

List<>

連想配列

NSMutableDictionary *	

Map<>

セマフォ生成

dispatch_semaphore_t semaphore = dispatch_semaphore_create(0);

Semaphore semaphore = new Semaphore(0);

セマフォ通知受信

dispatch_semaphore_wait(semaphore, DISPATCH_TIME_FOREVER);

try {
  semaphore.acquire();
} catch (
  InterruptedException ex) {
}

セマフォ通知

dispatch_semaphore_signal(semaphore);

semaphore.release();

特定文字で分割

NSArray *separated = [path componentsSeparatedByString:@"#"];

String[] separated = path.split(Pattern.quote("#"), 0);

特定文字置き換え

NSString *url = [aString stringByReplacingOccurrencesOfString:@"https://" withString:@""];

String url = aString.replaceAll("https://", "");

文字列の連結

NSString *entrys = [entrys stringByAppendingString:[NSString stringWithFormat:@"＜img src=%@ /＞", url]];

StringBuilder entrys = entrys.append(String.format("＜img src=%s /＞", url));

メソッドで変更した内容を引数で受け取る方法

NSString *mutableString;
[self method:&mutableString];

StringBuilder mutableString = new StringBuilder(aString);
method(mutableString);

文字列をtrancateする

NSString *subString = [aString substringWithRange:stringRange];

String subString = aString.substring（0, 8）;

printf構文で文字列を整形

NSString *url = [NSString stringWithFormat:@"https://aaa.com/%@/", text];

String url = String.format("https://aaa.com/%s/", text);

コレクション（配列、連想配列）操作

for (NSString * in NSArray) {
}

for(String s : Map) {
}

アラート表示

UIAlertController *alertController = [UIAlertController alertControllerWithTitle:nil message:NSLocalizedString(@"AlertMessage", @"") preferredStyle:UIAlertControllerStyleAlert];

[alertController addAction:[UIAlertAction actionWithTitle:NSLocalizedString(@"OK", @"") style:UIAlertActionStyleDefault handler:^(UIAlertAction *action) {
}]];

[self presentViewController:alertController animated:YES completion:^{
}];

new AlertDialog.Builder(this)
        .setTitle("")
        .setMessage(alertMessage)
        .setPositiveButton(R.string.Ok, new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
            }
        })
        .show();

メインスレッド(UIスレッド)で画面変更

dispatch_async(dispatch_get_main_queue(), ^{
});

Activity#runOnUiThread(new Runnable() {
  @Override
  public void run() {
  }
});

サブスレッドで実行

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
});

(new Thread(new Runnable() {
    @Override
    public void run() {
    }
})).start();

ローディングインジケータ表示 Loading Indicator

UIActivityIndicatorView *mIndicator;
[mIndicator startAnimating];

findViewById(R.id.loadingIndicator).setVisibility(VISIBLE);

＜ProgressBar
    android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    android:id="@+id/loadingIndicator"
    android:indeterminateOnly="true"
    android:keepScreenOn="true"
    android:layout_gravity="right|center_vertical"
    android:layout_marginRight="8dp"
    android:visibility="invisible" ／＞