CODEWITHSUNDEEP
objective-cfloating-pointnumbers
Ben
Ben

Reputation: 751

objective c float numer conversion

  float f2,f1 = 123.125;

what is different between them? 

  float f1 = 123.125,f2;

if I write code as 

float f1,f2 = 123.125

the program will has different result

here is the full program 

   float f2,f1 = 123.125;
    //float f1 = 123.125,f2;
    int i1,i2 = -150;

    i1 = f1; //floating to integer 
    NSLog(@"%f assigned to an int produces %i",f1,i1);

    f1 = i2; //integer to floating
    NSLog(@"%i assigned to a float produces %f",i2,f1);

    f1 = i2/100; //integer divided by integer
    NSLog(@"%i divied by 100 prouces %f",i2,f1);

    f2= i2/100.0; //integer divided by a float
    NSLog(@"%i divied by 100.0 produces %f",i2,f2);

    f2= (float)i2 /100; // type cast operator
    NSLog(@"(float))%i divided by 100 produces %f",i2,f2);

Upvotes: 1

Views: 157

Answers (2)

AndersK
AndersK

Reputation: 36082

  float f2,f1 = 123.125;  // here you leave f2 uninitialized and f1 is initialized

  float f1 = 123.125,f2;  // here you leave f2 uninitialized and f1 is initialized

  float f1,f2 = 123.125;  // here you leave f1 uninitialized and f2 is initialized

if you want to initialize both variables you need to do

  float f1 = 123.125f, f2 = 123.125f;

preferably you write like this (for readability)

  float f1 = 123.125f;
  float f2 = 123.125f;

note the "f" suffix, it indicates that it is a float value and not a double.

you can also do a define

#define INITVALUE 123.125f

float f1 = INITVALUE;
float f2 = INITVALUE;

Upvotes: 4

trojanfoe
trojanfoe

Reputation: 122381

If you want to initialise two variables with the same value then use this syntax:

float f2 = f1 = 123.125f;

The code you are using is initialising one of the variables and not the other, hence the behaviour you are seeing.

Upvotes: 0

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