Why javascript indexOf “empty string” always returning zero [duplicate]

问题

This question already has answers here:

indexOf empty string is zero. why? (1 answer)

Java String.indexOf and empty Strings (5 answers)

Closed 4 years ago.

Why javascript indexOf method always return 0 for empty string. If i used any string indexOf("") always returns zero. Any reason for this. Explain the reason briefley.

var str="jquery";
var index=str.indexOf("") \\ Always returns zero for any string.

Thanks in advance.

来源：https://stackoverflow.com/questions/28692565/why-javascript-indexof-empty-string-always-returning-zero