---
字符串相关
---

[05. 替换空格](https://leetcode-cn.com/problems/ti-huan-kong-ge-lcof/)

```java
class Solution {

    public String replaceSpace(String s) {
        StringBuilder builder = new StringBuilder();
        int i = 0;
        while (i < s.length()) {
            char c = s.charAt(i);
            if (c == ' ') {
                builder.append("%20");
            } else {
                builder.append(c);
            }
            i++;
        }
        return builder.toString();
    }
}
```