Properties of variables with null or undefined values should not be accessed
- NULL_POINTER
- Error
- High
- cwe
This rule applies when properties of variables with null or undefined values are accessed.
Trying to access properties of null or undefined variables causes a TypeError exception.
Noncompliant Code Example
View with compliant examples side by side// Example 1
function foo() {
var obj;
return obj.x; // NULL_POINTER alarm
}
// Example 2
if (x == null) { // (x == null) should be modified to (x != null).
y = x.a; // NULL_POINTER alarm: x is undefined or null but is property-accessed.
}
// Example 3
y = x || x.a; // NULL_POINTER alarm: x has a falsy value but is property-accessed.Compliant Code Example
View with noncompliant examples side by side// Example 1
function foo() {
var obj = { x: 1 }; // 'obj' should be initialized.
return obj.x;
}
// Example 2
if (x != null) {
y = x.a;
}
// Example 3
y = x && x.a;Version
This rule was introduced in DeepScan 1.0.0-alpha.