


The difference in output results of console.log: Why do the same variables have different printing methods but different results?
Detailed explanation of the difference in console.log output
This article analyzes the reasons why the output results of the console.log
function in a piece of code are different. Code snippets involve URL parameter parsing and usage of console.log
, and there are subtle but important differences in output results.
In the code, the getUrlParams
function parses the URL parameter and assigns redirectKey
parameter value to the variable redirectKey
. Then, the code uses console.log(2, redirectKey)
and console.log(redirectKey)
to print the value of redirectKey
, respectively.
The first method console.log(2, redirectKey)
output is 2 'bankList\n'
, and the second method console.log(redirectKey)
output is bankList
. The difference is that the first output contains a string wrapped in single quotes, which contains \n
newlines; the second output has no newlines.
This difference stems from the way console.log
handles multiple parameters. When console.log
receives multiple parameters, it converts the parameters to strings and then concatenates the output. In the first case, the value of redirectKey
contains \n
, the newline is preserved and wrapped in single quotes, clearly showing the existence of \n
. In the second case, although redirectKey
still contains \n
, console.log
only receives one parameter, and the browser directly interprets \n
as a newline when rendering, so \n
cannot be seen in the output, only bankList
is displayed. \n
has not disappeared, it still exists in the redirectKey
variable, but the browser's different processing methods of single-parameter and multi-parameter output lead to differences in display results. Carefully observe the single quote content of the first output result to verify.
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