Explanation of ReferenceError: expect is not defined
A ReferenceError occurs when a variable or function is used before it has been declared or assigned a value. It means that the interpreter couldn’t find a reference (or definition) for the identifier used in the code.
In the case of the error “ReferenceError: expect is not defined”, it means that the code is trying to use the identifier “expect” without having it declared or assigned a value.
Examples:
Example 1:
console.log(expect); // ReferenceError: expect is not defined
In this example, the code is trying to log the value of the variable “expect”. However, since the variable is not defined or declared, it results in a ReferenceError.
Example 2:
function test() {
console.log(expect); // ReferenceError: expect is not defined
}
test();
In this example, the code is inside a function called “test”. Again, it is trying to log the value of the variable “expect” which is not defined. When the function is called, it results in a ReferenceError.
To fix this error, you need to ensure that the identifier “expect” is properly declared or assigned a value before using it in the code. This could involve declaring variables using the “var”, “let”, or “const” keywords, or importing/requiring external modules that define the identifier.