Console
The console module provides a simple debugging console, which is similar to the JavaScript console provided by the browser.
NOTE
The initial APIs of this module are supported since API version 7. Newly added APIs will be marked with a superscript to indicate their earliest API version.
console.debug
static debug(message: string, ...arguments: any[]): void
Prints debugging information in formatted output mode.
Widget capability: This API can be used in ArkTS widgets since API version 9.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.ArkUI.ArkUI.Full
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| message | string | Yes | Text to be printed. |
| arguments | any[] | No | Arguments in the message or other information to be printed. |
Example
const number = 5;
console.debug('count: %d', number); // Print the debugging information with arguments in the message replaced.
// count: 5
console.debug('count:', number); // Print the message and other information.
// count: 5
console.debug('count:'); // Print the message only.
// count:
console.log
static log(message: string, ...arguments: any[]): void
Prints log information in formatted output mode.
Widget capability: This API can be used in ArkTS widgets since API version 9.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.ArkUI.ArkUI.Full
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| message | string | Yes | Text to be printed. |
| arguments | any[] | No | Arguments in the message or other information to be printed. |
Example
const number = 5;
console.log('count: %d', number); // Print the log information with arguments in the message replaced.
// count: 5
console.log('count:', number); // Print the message and other information.
// count: 5
console.log('count:'); // Print the message only.
// count:
console.info
static info(message: string, ...arguments: any[]): void
Prints log information in formatted output mode. This API is the alias of console.log ().
Widget capability: This API can be used in ArkTS widgets since API version 9.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.ArkUI.ArkUI.Full
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| message | string | Yes | Text to be printed. |
| arguments | any[] | No | Arguments in the message or other information to be printed. |
Example
const number = 5;
console.info('count: %d', number); // Print the log information with arguments in the message replaced.
// count: 5
console.info('count:', number); // Print the message and other information.
// count: 5
console.info('count:'); // Print the message only.
// count:
console.warn
static warn(message: string, ...arguments: any[]): void
Prints warning information in formatted output mode.
Widget capability: This API can be used in ArkTS widgets since API version 9.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.ArkUI.ArkUI.Full
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| message | string | Yes | Warning information to be printed. |
| arguments | any[] | No | Arguments in the message or other information to be printed. |
Example
const str = "name should be string";
console.warn('warn: %d', str); // Print the warning information with arguments in the message replaced.
// warn: name should be string
console.warn('warn:', str); // Print the message and other information.
// warn: name should be string
console.warn('warn:'); // Print the message only.
// warn:
console.error
static error(message: string, ...arguments: any[]): void
Prints error information in formatted output mode.
Widget capability: This API can be used in ArkTS widgets since API version 9.
Atomic service API: This API can be used in atomic services since API version 11.
System capability: SystemCapability.ArkUI.ArkUI.Full
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| message | string | Yes | Error information to be printed. |
| arguments | any[] | No | Arguments in the message or other information to be printed. |
Example
const str = "value is not defined";
console.error('error: %d', str); // Print the error information with arguments in the message replaced.
// error: value is not defined
console.error('error:', str); // Print the message and other information.
// error: value is not defined
console.error('error:'); // Print the message only.
// error:
console.assert10+
static assert(value?: Object, ...arguments: Object[]): void
Prints assertion information.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| value | Object | No | Result value. If value is false or left blank, the output starting with "Assertion failed" is printed. If value is true, no information is printed. |
| arguments | Object | No | Other information to be printed when value is false. If this parameter is left blank, no information is printed. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1.Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed. |
Example
console.assert(true, 'does nothing'); // Do not print error information as value is true.
console.assert(2 % 1 == 0, 'does nothing'); // Do not print error information as value is true.
console.assert(false, 'console %s work', 'didn\'t');
// Assertion failed: console didn't work
console.assert();
// Assertion failed
console.count10+
static count(label?: string): void
Maintains an internal counter. When this counter is invoked, its label name and the corresponding call count are printed.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| label | string | No | Counter label name. The default value is default. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1.Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed. |
Example
console.count()
// default: 1
console.count('default')
// default: 2
console.count('abc')
// abc: 1
console.count('xyz')
// xyz: 1
console.count('abc')
// abc: 2
console.count()
// default: 3
console.countReset10+
static countReset(label?: string): void
Resets a counter based on the specified label name.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| label | string | No | Counter label name. The default value is default. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1.Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed. |
Example
console.count('abc');
// abc: 1
console.countReset('abc');
console.count('abc');
// abc: 1
console.dir10+
static dir(dir?: Object): void
Prints content of the specified object.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| dir | Object | No | Object whose content needs to be printed. If this parameter is left blank, no information is printed. |
Example
class bar {
baz: boolean = true;
}
let b: bar = {baz: true}
class foo{
bar: bar = b;
}
let c: foo = {bar: b}
class c1{
foo: foo = c;
}
let a: c1 = {foo: c}
console.dir(a);
// Object: {"foo":{"bar":{"baz":true}}}
console.dir(); // No information is printed.
console.dirxml10+
static dirxml(...arguments: Object[]): void
Displays an interactive tree of the descendant elements of the specified XML element. This API is implemented by calling console.log() internally. It does not produce any XML elements. The usage method is the same as that of console.log().
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| arguments | Object | No | Information to be printed. If this parameter is left blank, no information is printed. |
Example
const number = 5;
console.dirxml('count: %d', number);
// count: 5
console.dirxml('count:', number);
// count: 5
console.dirxml('count:');
// count:
console.group10+
static group(...arguments: Object[]): void
Increases the indentation of subsequent lines by two spaces.
If the information to be printed is provided, the information is printed without extra indentation.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| arguments | Object | No | Information to be printed. If this information is omitted, only two spaces are printed. |
Example
console.info("outer");
// outer
console.group();
console.info("level 1");
// level 1
console.group("in level1");
// in level1
console.info("level 2");
// level 2
console.groupCollapsed10+
static groupCollapsed(...arguments: Object[]): void
Creates a new inline group in collapsed mode. The usage and function of this API are the same as those of console.group().
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| arguments | Object | No | Information to be printed. If this information is omitted, only two spaces are printed. |
Example
console.groupCollapsed("outer");
// outer
console.groupCollapsed();
console.info("level 1");
// level 1
console.groupCollapsed("in level1");
// in level1
console.info("level 2");
// level 2
console.groupEnd10+
static groupEnd(): void
Reduces the indentation of subsequent lines by two spaces.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Example
console.info("outer");
// outer
console.group();
console.info("level 1");
// level 1
console.groupEnd();
console.info("outer");
// outer
console.table10+
static table(tableData?: Object): void
Prints data in a table.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| tableData | Object | No | Data to be printed in a table. If this parameter is left blank, no information is printed. |
Example
console.table([1, 2, 3]);
// ┌─────────┬────────┐
// │ (index) │ Values │
// ├─────────┼────────┤
// │ 0 │ 1 │
// │ 1 │ 2 │
// │ 2 │ 3 │
// └─────────┴────────┘
console.table({ a: [1, 2, 3, 4, 5], b: 5, c: { e: 5 } });
// ┌─────────┬───┬───┬───┬───┬───┬───┬────────┐
// │ (index) │ 0 │ 1 │ 2 │ 3 │ 4 │ e │ Values │
// ├─────────┼───┼───┼───┼───┼───┼───┼────────┤
// │ a │ 1 │ 2 │ 3 │ 4 │ 5 │ │ │
// │ b │ │ │ │ │ │ │ 5 │
// │ c │ │ │ │ │ │ 5 │ │
// └─────────┴───┴───┴───┴───┴───┴───┴────────┘
console.time10+
static time(label?: string): void
Starts a timer to track the duration of an operation. You can use console.timeEnd() to close the timer and print the elapsed time (in ms).
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| label | string | No | Timer label. The default value is default. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1.Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed. |
Example
console.time('abc');
console.timeEnd10+
static timeEnd(label?: string): void
Stops the timer started by calling console.time() and prints the elapsed time (in ms).
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| label | string | No | Timer label. The default value is default. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1.Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed. |
Example
console.time('abc');
console.timeEnd('abc');
// abc: 225.438ms
console.timeLog10+
static timeLog(label?: string, ...arguments: Object[]): void
Prints the elapsed time and other data parameters for the timer started by console.time().
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| label | string | No | Timer label. The default value is default. |
| arguments | Object | No | Logs to be printed. |
Error codes
For details about the error codes, see Universal Error Codes.
| ID | Error Message |
|---|---|
| 401 | Parameter error. Possible causes: 1.Mandatory parameters are left unspecified; 2. Incorrect parameter types; 3. Parameter verification failed. |
Example
console.time('timer1');
console.timeLog('timer1', 17);
// timer1: 365.227ms 17
console.timeEnd('timer1');
// timer1: 513.22ms
console.trace10+
static trace(...arguments: Object[]): void
Creates a stack trace.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Parameters
| Name | Type | Mandatory | Description |
|---|---|---|---|
| arguments | Object | No | Logs to be printed. If this parameter is left blank, only stack information is printed. |
Example
console.trace();
// Trace:
// xxxxxxxxxx (current stack information)
console.trace("Show the trace");
// Trace: Show the trace
// xxxxxxxxxx (current stack information)
console.traceHybridStack12+
static traceHybridStack(): void
Prints information about the current hybrid stack of the calling thread in the main thread or worker thread.
Atomic service API: This API can be used in atomic services since API version 12.
System capability: SystemCapability.Utils.Lang
Example
console.traceHybridStack();
// TraceHybridStack:
// xxxxxxxxxx (information about the current hybrid stack of the calling thread)