Python程序查找字符串中字符的第一次出现

编写一个 Python 程序，通过实际示例查找字符串中字符的第一次出现。

Python程序查找字符串中字符的第一次出现示例

此 Python 程序 允许用户输入 一个字符串和一个字符。

请参阅 字符串 文章，了解有关 Python 字符串的所有信息。

# Python Program to check First Occurrence of a Character in a String

string = input("Please enter your own String : ")
char = input("Please enter your own Character : ")

flag = 0
for i in range(len(string)):
    if(string[i] == char):
        flag = 1
        break

if(flag == 0):
    print("Sorry! We haven't found the Search Character in this string ")
else:
    print("The first Occurrence of ", char, " is Found at Position " , i + 1)

Python 字符串中字符的第一次出现输出

Please enter your own String : hello world
Please enter your own Character : l
The first Occurrence of  l  is Found at Position  3

在这里，我们使用 For Loop 来迭代字符串中的每个字符。在 For Loop 中，我们使用 If statement 来检查 str1 字符串中的任何字符是否等于字符 ch。如果为真，则 flag = 1，并执行 Break statement。

string = hello world
ch = l
flag = 0

For Loop 第一次迭代：for i in range(11)
if(string[i] == char)
if(h == l) – 条件为假。

第二次迭代：for 1 in range(11)
if(e == l) – 条件为假。

第三次迭代：for 2 in range(11)
if(str[2] == ch) => if(l == l) – 条件为真。

Flag  = 1 并执行 break 语句退出循环。接下来，我们使用 If Else Statement 来检查 flag 值是否等于 0。在这里，条件为假。因此，执行 else 块中的打印语句。

Python程序查找字符串中字符的第一次出现示例 2

此 Python 字符串中字符的第一次出现 程序 与上面的程序相同。但是，我们只是用 While Loop 替换了 For Loop。

# Python Program to check First Occurrence of a Character in a String

string = input("Please enter your own String : ")
char = input("Please enter your own Character : ")
i = 0
flag = 0

while(i < len(string)):
    if(string[i] == char):
        flag = 1
        break
    i = i + 1

if(flag == 0):
    print("Sorry! We haven't found the Search Character in this string ")
else:
    print("The first Occurrence of ", char, " is Found at Position " , i + 1)

Python 字符串中字符的第一次出现输出

Please enter your own String : python programming
Please enter your own Character : o
The first Occurrence of  o  is Found at Position  5

Python程序获取字符串中字符的第一次出现示例 3

此 Python 程序 用于查找字符串中字符的第一次出现，与第一个示例相同。但是，这次我们使用了 Functions 概念来分离逻辑。

# Python Program to check First Occurrence of a Character in a String

def first_Occurrence(char, string):
    for i in range(len(string)):
        if(string[i] == char):
            return i
    return -1

str1 = input("Please enter your own String : ")
ch = input("Please enter your own Character : ")

flag =  first_Occurrence(ch, str1)
if(flag == -1):
    print("Sorry! We haven't found the Search Character in this string ")
else:
    print("The first Occurrence of ", ch, " is Found at Position " , flag + 1)
Python Program to find First Occurrence of a Character in a String