Question

i am doing a project in android. i am a begineer in android also. in my android application i am using php as my webservice provider. in my php code for the authentication i am check the user vaidity and return string 1 or 0. In android application i am get the string. but when i check it in a if condition it fails. is it due to any charset compatablity issue.

in php code

.....
if($auth) {
 echo '1';
}
else {
 echo '0';
}

in android

//get the code and saved in to string loginStatus;
if(loginStatus == "1") {
 //not getting into this part if the loginStatus is 1;
}
else {
 //getting into this part
}

Answer 1

The == operator checks to see if two string references point to exactly the same string instance. So even if you have two strings that both have the value "1" the == operator can still return false.

To compare the strings character-by-character use String.equals:

if (loginStatus.equals("1")) {

---

To see the difference between == and equals see this simplified example:

String a = new String("1");
String b = new String("1");
System.out.println("a == b: " + (a == b));
System.out.println("a.equals(b): " + a.equals(b));

Result:

a == b: false
a.equals(b): true

See this code running online: ideone

---

Note: if loginStatus can be null you also need to check for that too, or else reverse the order of the strings so that the constant string is first:

if (loginStatus != null && loginStatus.equals("1")) {

Or:

if ("1".equals(loginStatus)) {