Strings, just like any other Object, should be compared using the equals() method.

Using == and != compares references rather than values, and usually does not work.

Noncompliant Code Example

if (variable == "foo") { /* ... */ }
if (variable != "foo") { /* ... */ }

Compliant Solution

if ("foo".equals(variable)) { /* ... */ }    // Compliant
if (!"foo".equals(variable)) { /* ... */ }   // Compliant

See

• MITRE, CWE-597 - Use of Wrong Operator in String Comparison

This rule is deprecated, use {rule:squid:S1698} instead.