java和python相当于php的foreach（$ array as $ key => $ value） [英] java and python equivalent of php's foreach($array as $key => $value)

问题描述

在php中，可以使用关联数组来处理状态名称及其缩写的列表，如下所示：

 < ？php 
 $ stateArray = array（
ALABAMA=>AL，
ALASKA=>AK，
 //等等... 
WYOMING=>WY
）; 
 
 foreach（$ stateArray as $ stateName => $ stateAbbreviation）{
 print$ stateName的缩写是$ stateAbbreviation.\\\
\ n; 
} 
？> 
  

输出（保留密钥订单）：

< pre class =lang-none prettyprint-override> ALABAMA的缩写是AL。

ALASKA的缩写是AK。

WYOMING的缩写是WY。


编辑：注意数组元素的顺序保留在php版本的输出中。使用HashMap的Java实现不保证元素的顺序。 Python中的字典也没有。

这是如何在java和python中完成的？我只找到提供价值的方法，给定密钥，如python的：

  stateDict = {
ALASKA ：AK，
WYOMING：WY，
} 
 
 for state in stateDict：
 value = stateDict [key] 
  

---

编辑：基于答案，这是我在python中的解决方案，

 ＃一个两元组的列表
 stateList = [
（'ALABAMA'，'AL'） ，
（'ALASKA'，'AK'），
（'WISCONSIN'，'WI'），
（'WYOMING'，'WY'），
] $ b名称为
 $ b，stateList为缩写：
打印名称，缩写
  

输出：

  ALABAMA AL 
 ALASKA AK 
 WISCONSIN WI 
 WYOMING WY 
  

这正是所需要的。

解决方案Python中的

：

  for key，value in stateDict.items（）：＃。ititeitems（）在P. ython 2.x 
 print％s的缩写是％s。 Java中的％（键，值）
  

：

 地图<字符串，字符串> stateDict; 
 
 for（Map.Entry< String，String> e：stateDict.entrySet（））
 System.out.println（+ e.getKey（）+的缩写是+ e.getValue（）+。）; 
  

In php, one can handle a list of state names and their abbreviations with an associative array like this:

<?php
    $stateArray = array(
        "ALABAMA"=>"AL",
        "ALASKA"=>"AK",
        // etc...
        "WYOMING"=>"WY"
    );

    foreach ($stateArray as $stateName => $stateAbbreviation){
        print "The abbreviation for $stateName is $stateAbbreviation.\n\n";
    }
?>

Output (with key order preserved):

The abbreviation for ALABAMA is AL.

The abbreviation for ALASKA is AK.

The abbreviation for WYOMING is WY.

EDIT: Note that the order of array elements is preserved in the output of the php version. The Java implementation, using a HashMap, does not guarantee the order of elements. Nor does the dictionary in Python.

How is this done in java and python? I only find approaches that supply the value, given the key, like python's:

stateDict = {
    "ALASKA": "AK",
    "WYOMING": "WY",
}

for key in stateDict:
    value = stateDict[key]

---

EDIT: based on the answers, this was my solution in python,

# a list of two-tuples
stateList = [
    ('ALABAMA', 'AL'),
    ('ALASKA', 'AK'),
    ('WISCONSIN', 'WI'),
    ('WYOMING', 'WY'),
]

for name, abbreviation in stateList:
    print name, abbreviation

Output:

ALABAMA AL
ALASKA AK
WISCONSIN WI
WYOMING WY

Which is exactly what was required.

解决方案

in Python:

for key, value in stateDict.items(): # .iteritems() in Python 2.x
    print "The abbreviation for %s is %s." % (key, value)

in Java:

Map<String,String> stateDict;

for (Map.Entry<String,String> e : stateDict.entrySet())
    System.out.println("The abbreviation for " + e.getKey() + " is " + e.getValue() + ".");

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