Question

我用一些例子来解释我的问题：

例1：

var str = "this is a test
           and also this is a test
           and this";

范围：[19 - 22] // "also"

现在，我需要检查str从19的起始位置和22直到该字符串末尾的$作为此字符true。如果有，则返回false，否则返回false。在这种情况下，输出是：

var str = "this $ is a test
           and also this is a test
           and this";

例2：

[21 - 24] // "also"

范围：false // there is $ before the range, but there isn't after it, so false

输出：

var str = "this $ is a test
           and also this is a test
           and $this";

示例3：

[21 - 24] // "also"

范围：true

输出：

var str = "this $ is $ a test
           and also this is a test
           and $ this";

范例4：

[23 - 26] // "also"

范围：false // there is two $ before the range and that means there isn't $ before the range, so false

输出：

var str = "this $ is $ $ a test
           and also this is a test
           and $ this";

举例5：

[25 - 27] // "also"

范围：true

输出：

indexOf()

注意：我不需要使用FreeOnTerminate获取该范围，我已经拥有这些职位。

我该怎么做？

Answer 1

var n= str.indexOf("also");
var pre=(str.substring(0,n).match(/\$/g) || []).length;
var post=(str.substring(n+3,str.length).match(/\$/g) || []).length;
if(pre %2 ===1 && post %2===1){
console.log(true)
} else {
console.log(false);
}

如何确定某个位置是否在特定字符之间？

1 个答案: