Where is Java’s Array indexOf?

There are a couple of ways to accomplish this using the Arrays utility class.

If the array is not sorted and is not an array of primitives:

java.util.Arrays.asList(theArray).indexOf(o)

If the array is primitives and not sorted, one should use a solution offered by one of the other answers such as Kerem Baydoğan’s, Andrew McKinlay’s or Mishax’s. The above code will compile even if theArray is primitive (possibly emitting a warning) but you’ll get totally incorrect results nonetheless.

If the array is sorted, you can make use of a binary search for performance:

java.util.Arrays.binarySearch(theArray, o)

Related Posts:

  1. How do I determine whether an array contains a particular value in Java?
  2. How to initialize an array in Java?
  3. Initialize part of an array in java
  4. How do I declare and initialize an array in Java?
  5. Convert list to array in Java [duplicate]
  6. Sort an array in Java
  7. What’s the simplest way to print a Java array?
  8. Explanation on Integer.MAX_VALUE and Integer.MIN_VALUE to find min and max value in an array
  9. What’s the simplest way to print a Java array?
  10. Converting array to list in Java
  11. Java Error “Exception in thread “main” java.util.InputMismatchException” On an Array program
  12. Converting String to “Character” array in Java
  13. Java Error “Exception in thread “main” java.util.InputMismatchException” On an Array program
  14. Create ArrayList from array
  15. How do I reverse an int array in Java?
  16. How to split a String by space
  17. Print ArrayList
  18. Print ArrayList
  19. Make copy of an array
  20. How to create a sub array from another array in Java?
  21. How to fix array index out of bounds error?
  22. Array ArrayList python equivalent
  23. Double array initialization in Java
  24. Java – Best way to print 2D array?
  25. java Arrays.sort 2d array
  26. I want to declare an empty array in java and then I want do update it but the code is not working
  27. method in class cannot be applied to given types
  28. How to convert an ArrayList containing Integers to primitive int array?
  29. Error: can only iterate over an array or an instance of java.lang.Iterable
  30. Convert an integer to an array of characters : java
  31. How to efficiently remove duplicates from an array without using Set
  32. Print ArrayList
  33. Convert array of strings into a string in Java
  34. How do I do a deep copy of a 2d array in Java?
  35. Returning an empty array
  36. How to create an empty array?
  37. Finding the max/min value in an array of primitives using Java
  38. Will Arrays.sort() increase time complexity and space time complexity?
  39. How can I concatenate two arrays in Java?
  40. Java – Best way to print 2D array?
  41. What is the difference between a null array and an empty array?
  42. method in class cannot be applied to given types
  43. How can I create an Array of ArrayLists?
  44. Are arrays passed by value or passed by reference in Java?
  45. How can I check whether an array is null / empty?
  46. Shifting array to the right – homework
  47. Add an object to an Array of a custom class
  48. Random shuffling of an array
  49. How to convert int[] to Integer[] in Java?
  50. Exception in thread “main” java.lang.ArrayIndexOutOfBoundsException
  51. what is Ljava.lang.String;@
  52. “Cannot create generic array of ..” – how to create an Array of Map?
  53. Convert String to int array in java
  54. “Actual or formal argument lists differs in length”
  55. Java Comparator class to sort arrays
  56. Resize an Array while keeping current elements in Java?
  57. List of Arrays in Java
  58. How to sort an array of objects in Java?
  59. How to sort an array of objects in Java?
  60. local variables referenced from an inner class must be final or effectively final
  61. Bank Account Java Program
  62. What is the default initialization of an array in Java?
  63. Java, Shifting Elements in an Array
  64. Counting an Occurrence in an Array (Java)
  65. How to make an array of arrays in Java
  66. How to create a generic array in Java?
  67. Empty an array in Java / processing
  68. Java, Simplified check if int array contains int
  69. Error: Generic Array Creation
  70. Add String Array to ArrayList
  71. How to print the data in byte array as characters?
  72. Java Array Sort descending?
  73. Java read file and store text in an array
  74. (Java) Tic-Tac-Toe game using 2 dimensional Array
  75. int cannot be converted to int []
  76. Finding the size of a char array in Java
  77. Any way to declare an array in-line?
  78. Getting the array length of a 2D array in Java
  79. Get only part of an Array in Java?
  80. Checking to see if array is full
  81. How to use ArrayUtils for array of objects, it doesn’t delete the content of an array
  82. Error array dimension missing
  83. Printing char arrays in Java
  84. Fill an array with random numbers [duplicate]
  85. Create a two dimensional string array anArray[2][2]
  86. Printing array elements with a for loop
  87. How do I convert this for loop into a while loop?
  88. How do I initialize a byte array in Java?
  89. How do you set one array’s values to another array’s values in Java?
  90. java.lang.ArrayIndexOutOfBoundsException: 0
  91. How to increase the size of an array in Java?
  92. How to add an element at the end of an array?
  93. How to get rows and columns count of a 2D array in Java?
  94. Multidimensional Arrays lengths in Java
  95. creating array without declaring the size – java
  96. Hadoop “Unable to load native-hadoop library for your platform” warning
  97. How can I convert integer into float in Java?
  98. Convert boolean to int in Java
  99. How to convert a String to CharSequence?
  100. Java error “Value of local variable is not used”

Leave a Comment