The variable $j does not seem to be defined for all execution paths leading up to this point.
If you define a variable conditionally, it can happen that it is not defined
for all execution paths.
Let’s take a look at an example:
functionmyFunction($a){switch($a){case'foo':$x=1;break;case'bar':$x=2;break;}// $x is potentially undefined here.echo$x;}
In the above example, the variable $x is defined if you pass “foo” or “bar”
as argument for $a. However, since the switch statement has no default
case statement, if you pass any other value, the variable $x would be undefined.
Available Fixes
Check for existence of the variable explicitly:
functionmyFunction($a){switch($a){case'foo':$x=1;break;case'bar':$x=2;break;}if(isset($x)){// Make sure it's always set.echo$x;}}
Define a default value for the variable:
functionmyFunction($a){$x='';// Set a default which gets overridden for certain paths.switch($a){case'foo':$x=1;break;case'bar':$x=2;break;}echo$x;}
Add a value for the missing path:
functionmyFunction($a){switch($a){case'foo':$x=1;break;case'bar':$x=2;break;// We add support for the missing case.default:$x='';break;}echo$x;}
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$this->V[$this->n - 1][$this->n - 1] = 1.0;
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$this->e[0] = 0.0;
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}
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/**
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* Symmetric tridiagonal QL algorithm.
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*
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* This is derived from the Algol procedures tql2, by
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* Bowdler, Martin, Reinsch, and Wilkinson, Handbook for
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* Auto. Comp., Vol.ii-Linear Algebra, and the corresponding
php-ai /
php-ml
Mustafa Karabulut
If you define a variable conditionally, it can happen that it is not defined for all execution paths.
Let’s take a look at an example:
In the above example, the variable $x is defined if you pass “foo” or “bar” as argument for $a. However, since the switch statement has no default case statement, if you pass any other value, the variable $x would be undefined.
Available Fixes
Check for existence of the variable explicitly:
Define a default value for the variable:
Add a value for the missing path: