PhpStorm 2023.2 Help

Examine a suspended program

After the debugger session has started, the Debug tool window will appear, and the program will run normally until one of the following happens:

After that, the program is suspended, allowing you to examine its current state, control its further execution, and test various scenarios at runtime.

Examine frames

The state of the program is represented by frames. When the program is suspended, the current frame stack is displayed on the Frames tab of the Debug tool window.

Frames tab

A frame corresponds to the active method or function call. It stores the local variables of the called method or function, its arguments, and the code context that enables expression evaluation.

Each time a method is called, a new frame is added to the top of the stack. When the execution of a method is complete, the corresponding frame is removed from the stack (in the last in, first out fashion).

Examining frames helps you understand why particular parameters were passed to a method and what the state of the caller was at the time of calling.

Copy stack to clipboard

  • To copy the call stack for the current thread, right-click anywhere on the Frames tab and select Copy Stack.

Examine/update variables

The Variables tab shows the list of the variables in the selected frame/thread. Examining the variables can help you understand why the program operates in a certain way.

The Variables tab shows you the variables visible from the current execution point

The icon on the left of each variable indicates its type.

User-defined constants are grouped under a separate Constants node, which is by default collapsed. Once expanded or collapsed, the Constants node preserves this state across the debugging sessions. Note that if the number of user-defined constants is significant, the stepping performance might decrease. If necessary, you can disable fetching such constants during the debugging session by clicking the Show user-defined constants button on the Debug tool window toolbar. The Constants node will be hidden.

Copy variables

When examining variables, you may need to copy a variable name or value to paste it somewhere else or to compare it with another variable.

  • To copy the value that a variable holds, right-click the variable and select Copy Value Control+C.

  • To copy the name of a variable, right-click the variable and select Copy Name.

Compare variables with clipboard

When you need to compare a variable value with some other value, use the Compare Value with Clipboard option. This is helpful, for example, when a variable holds a long string, and you need to compare it with another long string.

  1. Copy the content you want to compare (for example, from a text file).

  2. In the Variables tab, right-click the variable that you want to compare with and select Compare Value with Clipboard.

  3. Examine the differences in the Diff Viewer that opens. For more information about efficient using of the Diff Viewer, refer to the Comparing Files and Folders topic.

View variables in a dedicated dialog

PhpStorm allows you to inspect variables in a dedicated dialog. This is useful when you need to keep track of some variable (or the object whose reference it holds) and at the same time be able to navigate between frames and threads.

  • Right-click a variable or a watch and select Inspect.

    Inspect dialog

Set variable values

If you want to test how the program would behave in certain conditions or fix its current behavior at runtime, you can do that by setting/changing the variable values.

  1. Select a variable and press F2. Alternatively, select Set Value from the context menu.

  2. Enter the value for the variable and press Enter.

    Enter new value for the variable in the field right next to its name

If you need to look into the source code where some variable or class is declared, you can move there right from the Variables pane.

  • To navigate to the code where the variable is declared, right-click the variable and select Jump to Source F4.

  • To navigate to the class declaration of the variable type, right-click the variable and select Jump to Type Source Shift+F4.

    Suppose, you have $my_car = new Car();. If you select $my_car in the Variables pane, then choosing Jump To Source will bring you to $my_car = new Car(); while choosing Jump To Type Source will bring you to class Car().

  • To navigate to the callback function declaration from a calling element, click Navigate next to this element on the Variables pane.

    Clicking Navigate takes you to the code of the corresponding callback function

Evaluate expressions

PhpStorm lets you evaluate expressions during a debugging session to obtain additional details about the program state or test various scenarios at runtime.

Evaluate a simple expression in the editor

To quickly evaluate an expression, point at it in the editor. Note that method calls cannot be evaluated this way.

  1. Point at the expression you want to evaluate. The result of the expression appears in a tooltip.

    Value tooltip
  2. To view child elements , click the Expand button or press Control+F1.

    Value tooltip

If you find value tooltips distracting, you can increase the delay or disable them altogether. To do this, in the Settings dialog (Control+Alt+S), go to Build, Execution, Deployment | Debugger | Data Views and set the Show value tooltip and Value tooltip delay options as required.

Evaluate a complex expression in the editor

If you want to evaluate an expression in the code that involves a method call, or you want to be specific about which portion of expression to evaluate, use the Quick Evaluate Expression option.

  1. Place the caret at the expression (to evaluate the closest matching expression) or select a portion of it (if you want to be specific about which part of a complex expression to evaluate).

  2. Click Run | Debugging Actions | Quick Evaluate Expression Control+Alt+F8.

    Value tooltip appears

You can configure Quick Evaluate to work for a piece of code on just selecting it (without using the menu/shortcut). Use this option carefully, as you can accidentally call methods when it is enabled.

To configure Quick Evaluate on code selection, go to Settings | Build, Execution, Deployment | Debugger | Data Views and set the Show value tooltip on code selection option as preferred.

Evaluate arbitrary expressions

Evaluating arbitrary expressions is the most flexible evaluating option. It lets you evaluate any code as long as it is in the context of the current frame. Using it, you can evaluate declarations, method calls, anonymous classes, lambdas, loops, and so on.

Use this feature to get additional information about the current state of the program and test various scenarios all within the same debugging session. This saves a lot of time by reducing the number of sessions you have to run.

  1. If you want to start with some expression or a variable, which is currently in front of you (for example, in the editor or on the Variables pane), select it.

    Select the expression to start from
  2. Click Run | Debugging Actions | Evaluate Expression Alt+F8. The shortcut may not work on Ubuntu (for correct operation, adjust the shortcut configuration).

  3. In the Evaluate dialog, modify the selected expression or enter a new one in the Expression field. Click Expand Shift+Enter to modify a multiline code fragment.

    The expression is entered in the Code Fragment field
  4. Click Evaluate (Control+Enter for multiline mode). The expression result appears in the Result field.

    The result of the expression is taken from the return statement. When there is no return statement, the result is taken from the last line of code (it does not even have to be an expression: a single literal works too). When there is no valid line to take the value from, the result is undefined. If the specified expression cannot be evaluated, the Result field indicates the reason.

    Expression result is calculated

The Evaluate dialog is non-modal, so you can switch the focus back to the editor to copy other variables and expressions. You can also open multiple Evaluate dialogs if necessary.

Evaluate variables in the Console

In the PHP and JavaScript context, you can view the values of variables during a debugging session by using the interactive console.

  • Select the variable in the Variables pane and choose Evaluate in Console from the context menu of the selection.

    When you switch to the Console pane, the variable name is shown in green at > and its value is displayed below in blue.

    Debug console output
  • Click the Use Console Input the Use Console Input button toggle button and type the name of any variable at > in the Console and press Enter to have its value displayed.

    Code completion Control+Space is available: as you type the name of a variable, PhpStorm displays a suggestion list.

  • To evaluate a previously evaluated variable, find it using the Up and Down arrows on you keyboard and press Enter.

Execute code in the Console

During a PHP debugging session, you can not only evaluate variables, but also change their values, call PHP functions, and define additional ones right in the Console pane. Note that this functionality is not available for Behat run/debug configurations.

  1. On the Console pane of the Debug tool window, click the Use Console Input toggle button the Use Console Input button on the toolbar.

    • When this toggle-button appears pressed, you can evaluate and alter variables, call PHP functions, and define additional functions on the fly in the Console pane.

    • When the toggle-button appears non-pressed, any input in the Console pane is treated like STDIN.

  2. Type a statement or expression at > and press Enter. PhpStorm evaluates your code fragment and shows the output below the input code. You can type most PHP constructs including class declarations, function declarations, variables, expressions, and so on. Code completion Control+Space is available: as you type, PhpStorm displays a suggestion list.

  3. When typing a multi-line code fragment, press Shift+Enter to start a new line and Control+Enter to split a line.

  4. Output for arrays and objects is by default wrapped in a var_export() function and displayed in the Console. To hide the output displayed, clear the Show array and object children in Debug Console checkbox on the Debug page.

View values inline

PhpStorm shows the values of the variables right next to their usage.

Once the variable value has changed, the inline view is updated with the new value and changes its color.

Inline values of the variables change with each step

If a line contains a reference to an object, you can examine its properties right in the editor. From this popup, you can also change the variable values and add inline watches.

Inline debugger hints

The inline view is enabled by default. To turn it off, in the Settings dialog (Control+Alt+S), go to Build, Execution, Deployment | Debugger | Data Views and disable the Show values inline option.

Add an Inline Watch

If you want the result of some expression to appear on a particular line, you can set up an inline watch for that. Inline watches are persistent and remain active after session restart.

  1. Click the inline hint referring to the object whose property you want to track.

  2. In the popup, select the property and click Add as Inline Watch.

    Adding an inline watch option
  3. Fine-tune the watch if needed. You can use any valid expression as a watch.

    Setting an inline watch

Inline watches you set in the editor are also shown under Inline Watches in the Variables pane of the Debug tool window.

To remove an inline watch, hover over the watch and click the cross near it.

View data flow analysis predictions

PhpStorm supports data flow analysis-assisted debugging in Xdebug sessions. Based on the information received from the debugger at a breakpoint, PhpStorm displays hints on what is going to happen in condition checks in the executed piece of code.

Hints showing the results of conditions

Blocks of code in the code path that are predicted to be unreachable during execution are grayed out.

Unreachable code blocks are grayed out

Disable inline prediction hints

  • For the current debugging session only: right-click any hint and select Turn Off Data Flow Assist.

    Turn Off Data Flow Assist
  • For all further debugging sessions: in the Settings dialog (Control+Alt+S), go to PHP | Debug and clear the Predict future condition values analyzing program data flow checkbox in the Xdebug area.

Disable graying out of unreachable code

  • In the Settings dialog (Control+Alt+S), go to PHP | Debug and clear the Gray out blocks of code that are predicted to be unreachable checkbox in the Xdebug area.

Watches

If you want to keep track of some variable or the result of a more complex expression, set up a watch for this variable or expression. This is useful when you need to add something that is not regularly displayed on the list of variables , or to pin some instance variable thus eliminating the need to expand the tree after each step.

Watches are evaluated in the context of the selected frame. Watches cannot be evaluated when they are out of context or when they fail to compile. If this is the case, the watch is marked with the error icon Error icon.

By default, watches are shown together with variables in the Variables pane. To hide/reveal the Watches pane, use the Separate watches option in the Layout Settingsthe Restore Layout button menu.

Add a watch

  1. Click New Watch New Watch button on the Watches tab.

  2. Enter the variable or expression to be evaluated. In expressions, you can evaluate method calls, lambdas declare variables, and so on, as long as this is in the local context.

    Watch expression

After you have added a variable/expression to Watches, it stays there and is evaluated for each step, providing you with the result in the current context.

Edit a watch

  • Right-click the desired watch and select Edit.

Copy a watch

  1. Select the watch you want to copy.

  2. Click Duplicate Watch Duplicate Watch button on the Variables/ Watches tab or press Control+D.

Change the order of watches

For convenience, you can change the order in which the watches appear on the Variables/ Watches pane.

  • Use the Move Watch Up/Move Watch Down buttons on the Variables/ Watches pane or Control+ArrowUp and Control+ArrowDown keyboard shortcuts.

Delete a watch

  • To remove a single watch, right-click it and select Remove Watch. Alternatively, select the watch and press Delete on the Variables/ Watches pane.

  • To remove all watches, right-click anywhere on the Variables/ Watches pane and select Remove All Watches.

Watches allow for the same actions as variables do. For example, you can view them in a dedicated dialog or use them to navigate to the source code.

Watches are a part of your project. This means you can stop and rerun the debugging session without risk of losing them.

Return to the current execution point

Examining the program state involves navigating in code, and you often need to return to the place where your program is suspended.

Do one of the following:

  • Go to Run | Debugging Actions | Show Execution Point.

  • Press Alt+F10.

  • Click The Show Execution Point button on the stepping toolbar of the Debug tool window.

The current execution point is indicated with a blue line. The code at this line has not been executed yet.

Blue line indicating the current execution point
Last modified: 12 September 2023