java - Cannot get a sum from a for loop -

here code:

public void checkout() {        double sum;     system.out.println("checking out items ...");      (int = 0; < purchases.length; i++) {         sum =+ purchases[i].getprice();         system.out.println(purchases[i].getdescription() + "/" + purchases[i].getprice());     }     system.out.println("amount due: " + "$" + new decimalformat("0.00").format(sum));  } 

when compile error:

the local variable sum may not have been initialized.

alternatively when change sum line double sum = sum + purchases[i].getprice();

i following error:

sum cannot resolved variable.

method takes list of items placed in shopping basket; prints items , individual price, finds total price (sum) of items.

can please tell me i'm doing wrong?

just initialize variable:

double sum = 0.0; 

in java, local method variable must initialized before being used. in case, have declared not initialized sum variable.

note error pretty descriptive: the local variable sum may not have been initialized. (emphasis mine).

alternatively when change sum line > double sum = sum + purchases[i].getprice(); error: sum cannot resolved variable. (emphasis , syntax/grammar fixes mine).

this because sum variable inside scope of for loop , you're using outside, wrong. compiler telling sum variable has never been declared before can't use it.

this problem (template only):

for(...) {     double sum = ... } //the compiler complain asking sum variable? system.out.println(sum); 

as stated in other answer, there error in addition code. fixing that, code this:

public void checkout(){        double sum = 0.0;     system.out.println("checking out items ...");      (int = 0; i<purchases.length; i++) {         sum += purchases[i].getprice();         system.out.println(purchases[i].getdescription() + "/" +             purchases[i].getprice());     }     system.out.println("amount due: " + "$" +new decimalformat("0.00").format(sum));  }