Is it possible to have String conditions in Calculated Number Field?

[Emmanuel Bautista III]

Is it possible to have String conditions in Calculated Number Field?

Please see below code:

<!-- @@Formula: 
double writeOffAmountFc = issue.get("customfield_19117");
double writeOffAmountUsd;

String currency = issue.get("customfield_10106");

if (currency == "IDR"){
writeOffAmountUsd = writeOffAmountFc / 13000;
}
if(currency == "THB"){
writeOffAmountUsd = writeOffAmountFc / 35;
}
if(currency == "MYR"){
writeOffAmountUsd = writeOffAmountFc / 4;
}
if(currency == "VND"){
writeOffAmountUsd = writeOffAmountFc / 23000;
}
if(currency == "RMB"){
writeOffAmountUsd = writeOffAmountFc / 7;
}
return writeOffAmountUsd;
-->