The toString()
method of Error
instances returns a string representing this error.
The toString()
method of Error
instances returns a string representing this error.
toString()
None.
A string representing the specified Error
object.
The Error
object overrides the Object.prototype.toString()
method inherited by all objects. Its semantics are as follows:
Error.prototype.toString = function () { if ( this === null || (typeof this !== "object" && typeof this !== "function") ) { throw new TypeError(); } let name = this.name; name = name === undefined ? "Error" : `${name}`; let msg = this.message; msg = msg === undefined ? "" : `${msg}`; if (name === "") { return msg; } if (msg === "") { return name; } return `${name}: ${msg}`; };
const e1 = new Error("fatal error"); console.log(e1.toString()); // "Error: fatal error" const e2 = new Error("fatal error"); e2.name = undefined; console.log(e2.toString()); // "Error: fatal error" const e3 = new Error("fatal error"); e3.name = ""; console.log(e3.toString()); // "fatal error" const e4 = new Error("fatal error"); e4.name = ""; e4.message = undefined; console.log(e4.toString()); // "" const e5 = new Error("fatal error"); e5.name = "hello"; e5.message = undefined; console.log(e5.toString()); // "hello"
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toString |
1 | 12 | 1 | 4 | 1 | 18 | 4 | 10.1 | 1 | 1.0 | 4.4 | 1.0 | 0.10.0 |
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https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/toString