JavaScript indexOf () method
Examples
Find an array of "Apple" elements:
var a = fruits.indexOf ( "Apple");
a result output:
The above output means that "Apple" in the array element at the second position.
try it"Definition and Usage
indexOf () method returns the position of a string value of the first occurrence of the specified string.
This method will retrieve a string from start to finish stringObject, to see if it contains a substring searchvalue. Start retrieving location (not specified fromindex time) at the beginning or at the fromindex string string. If you find a searchvalue, the position of the first occurrence of searchvalue is returned. stringObject character position is zero-based.
If you did not find the string in the array or -1.
Tip If you want to find the last occurrence of the string, use lastIndexOf () method .
Browser Support
All major browsers support indexOf () method, but Internet Explorer 8 and earlier versions of IE does not support this method.
grammar
Parameter Value
| 参数 | 描述 |
|---|---|
| item | 必须。查找的元素。 |
| start | 可选的整数参数。规定在字符串中开始检索的位置。它的合法取值是 0 到 stringObject.length - 1。如省略该参数，则将从字符串的首字符开始检索。 |
return value
| 类型 | 描述 |
|---|---|
| Number | 元素在数组中的位置,如果没与搜索到则返回 -1 |
technical details
| JavaScript version: | 1.6 |
|---|
More examples
Examples
Find an array "Apple" element in the fourth position of the array began to Search:
var a = fruits.indexOf("Apple",4);
a result output:
try it"