java convert float to String and String to float

Question

How could I convert from float to string or string to float   In my case I need to make the assertion between 2 values string  value that I have got from table  and float value that I have calculated   String valueFromTable    25   Float valueCalculated  25 0    I tried from float to string   String sSelectivityRate   String valueOf valueCalculated      but the assertion fails

User · Answer

If you re looking for  say two decimal places            Float f    float 12 34      String s   new DecimalFormat     00   format  f

User · Answer

Using Java   s Float class   float f   Float parseFloat  25    String s   Float toString 25 0f     To compare it s always better to convert the string to float and compare as two floats  This is because for one float number there are multiple string representations  which are different when compared as strings  e g   25      25 0      25 00  etc

User · Answer

You can try this sample of code   public class StringToFloat      public static void main  String   args              String s    fred         do this if you want an exception      String s    100 00        try             float f   Float valueOf s trim    floatValue          System out println  float f       f             catch  NumberFormatException nfe              System out println  NumberFormatException      nfe getMessage                   found here

User · Answer

I believe the following code will help   float f1   1 23f  String f1Str   Float toString f1         float f2   Float parseFloat f1Str

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To go the full manual route  This method converts doubles to strings by shifting the number s decimal point around and using floor  to long  and modulus to extract the digits  Also  it uses counting by base division to figure out the place where the decimal point belongs  It can also  quot delete quot  higher parts of the number once it reaches the places after the decimal point  to avoid losing precision with ultra-large doubles  See commented code at the end  In my testing  it is never less precise than the Java float representations themselves  when they actually show these imprecise lower decimal places         Convert the given double to a full string representation  i e  no scientific notation    and always twelve digits after the decimal point      param d The double to be converted     return A full string representation     public static String fullDoubleToString final double d           treat 0 separately  it will cause problems on the below algorithm     if  d    0            return  quot 0 000000000000 quot                find the number of digits above the decimal point     double testD   Math abs d       int digitsBeforePoint   0      while  testD  gt   1               doesn t matter that this loses precision on the lower end         testD    10d            digitsBeforePoint                create the decimal digits     StringBuilder repr   new StringBuilder           10  exponent to determine divisor and current decimal place     int digitIndex   digitsBeforePoint      double dabs   Math abs d       while  digitIndex  gt  0               Recieves digit at current power of ten    place in decimal number          long digit    long Math floor dabs   Math pow 10  digitIndex-1     10          repr append digit           --digitIndex                insert decimal point     if  digitIndex    0            repr append  quot   quot                  remove any parts above the decimal point  they create accuracy problems     long digit   0      dabs -   long Math floor dabs          Because of inaccuracy  move to entirely new system of computing digits after decimal place      while  digitIndex  gt  -12               Shift decimal point one step to the right         dabs    10d          final var oldDigit   digit          digit    long Math floor dabs    10          repr append digit               This may avoid float inaccuracy at the very last decimal places             However  in practice  inaccuracy is still as high as even Java itself reports             dabs -  oldDigit   10l          --digitIndex             return repr insert 0  d  lt  0    quot - quot     quot  quot   toString        Note that while StringBuilder is used for speed  this method can easily be rewritten to use arrays and therefore also work in other languages

User · Answer

There are three ways to convert float to String         f Float toString f  String valueOf f    There are two ways Convert String to float   Float valueOf str  Float parseFloat str     Example -  public class Test        public static void main String   args            System out println  convert FloatToString     convertFloatToString 34 0f             System out println  convert FloatToStr Using Float Method     convertFloatToStrUsingFloatMethod 23 0f             System out println  convert FloatToStr Using String Method     convertFloatToStrUsingFloatMethod 233 0f             float f   Float valueOf  23 00               public static String convertFloatToString float f            return      f             public static String convertFloatToStrUsingFloatMethod float f            return Float toString f              public static String convertFloatToStrUsingStringMethod float f            return String valueOf f

User · Answer

This is a possible answer  this will also give the precise data  just need to change the decimal point in the required form    public class TestStandAlone                   This method is to  main         param args  void             public static void main String   args               TODO Auto-generated method stub         try               Float f1 152 32f              BigDecimal roundfinalPrice   new BigDecimal f1 floatValue    setScale 2 BigDecimal ROUND HALF UP                System out println  f1 --    f1               String s1 roundfinalPrice toPlainString                System out println  s1   s1             catch  Exception e                   TODO Auto-generated catch block             e printStackTrace                         Output will be    f1 --  152 32 s1 152 32

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String str    1234 56   float num   0 0f   int digits   str length  - str indexOf      - 1   float factor   1f   for int i 0 i lt digits i    factor    10   for int i str length  -1 i gt  0 i--        if str charAt i                   factor   1          System out println  Reset  value   num           continue             num     str charAt i  -  0     factor      factor    10     System out println num

User · Answer

Float to string - String valueOf    float amount 100 00f  String strAmount String valueOf amount      or  Float toString float    String to Float - Float parseFloat    String strAmount  100 20   float amount Float parseFloat strAmount     or  Float valueOf string

User · Answer

well this method is not a good one  but easy and not suggested  Maybe i should say this is the least effective method and the worse coding practice but  fun to use   float val 10 0  String str val       the empty quotes  add a null string to the variable str  upcasting  val  to the string type

[java] java : convert float to String and String to float

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