Use StringBuilder and javastringbuilder for Java exercises

Use StringBuilder and javastringbuilder for Java exercises

1 package string. demo; 2 3/* 4 * convert the array into a String and output 5 */6 public class StringBuilderTest 7 {8 9/** 10 * @ param args11 */12 public static void main (String [] args) 13 {14 int [] arr = {2, 3, 41, 4}; 15 String str = arrayToString_2 (arr); 16 System. out. println (str); 17 18} 19 20 private static String arrayToString_2 (int [] arr) 21 {22 StringBuilder sb = new StringBuilder ("["); 23 for (int I = 0; I <arr. length; I ++) 24 {25 if (I! = Arr. length-1) 26 sb. append (arr [I] + ","); 27 else28 sb. append (arr [I] + "]"); 29} 30 return sb. toString (); 31} 32 33 public static String arrayToString_1 (int [] arr) 34 {35 String str = "["; 36 for (int I = 0; I <arr. length; I ++) 37 {38 if (I! = Arr. length-1) 39 str + = arr [I] + ","; 40 else41 str + = arr [I] + "]"; 42} 43 return str; 44} 45}