Loops in programming are used to automate similar tasks that will be repeated multiple times. For instance, if you\u2019re creating a program that merges together the price and name of all lunchtime menu items for a restaurant, you may want to use a loop to automate the task.
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In Java, This tutorial will discuss how to use Suppose you want to print the contents of an array that contains 100 items to the console. Or suppose you want to raise the price of everything in your store by 5 cents. Instead of doing these tasks manually, you would want to use a loop. In Java, Our loop has three components: These components are all required. Let\u2019s walk through an example to illustrate how Instead of calculating 1 * 10, 2 * 10, etc. individually, we can instead use a \u201cfor\u201d loop to calculate each value in the 10 times table. Here\u2019s the code we would use to calculate all values from 1-10 in the 10 times table: Our code returns: As you can see, our program has calculated all values in the 10 times table up to 10 * 10. Let\u2019s explore the code and discuss how it works step-by-step. First, we declare a class called TimesTable, which stores our code for this program. Then we create a Then, we print out a statement with the math problem and its answer. This statement is formatted as When you\u2019re working with an array and collection, there is another type of The syntax for the There are three components in our The Suppose you are operating a coffee shop, and you want to reduce the price of every coffee by 25 cents for a flash-sale. You have a list that contains the prices of each coffee, and you want to subtract 25 cents from each price. You could do so using the following code: Our code returns: As you can see, our program has reduced the price of every coffee by 50 cents. Now we have the data we need to change our coffee prices for the flash sale. Let\u2019s walk through our code step-by-step. First, we declare a class called ReducePrices, which stores our code for this example. Then we declare an array called Then we create a for<\/code> loops are used to repeat the execution of a block of code a certain number of times. Whereas while<\/code> loops run until a condition evaluates to false, for<\/code> loops run for a certain number of iterations.
<\/p>\n\n\n\nfor<\/code> and foreach<\/code> loops in Java, with reference to a few examples of for<\/code> and foreach<\/code> loops in Java programs.
<\/p>\n\n\n\nFor Loop Java<\/h2>\n\n\n\n
<\/p>\n\n\n\nfor<\/code> loops are used to run a specific task multiple times. Here\u2019s the syntax for a for<\/code> loop in Java:
<\/p>\n\n\n\nfor (initialization; expression; updateCounter) {\n\t\/\/ Execute code\n}<\/pre><\/div>\n\n\n\n
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<\/p>\n\n\n\nfor<\/code> loops work in Java. Suppose we are creating a program that allows a third-grader to find out the 10 times table. This program is used to help them revise for their upcoming math test.
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<\/p>\n\n\n\npublic class TimesTable {\n\tpublic static void main(String[] args) {\n\t\tfor (int i = 1; i <= 10; ++i) {\n\t\t\tint answer = i * 10;\n\t\t\tSystem.out.println(i + \" x 10 is \" + answer);\n\t\t}\n\t}\n}<\/pre><\/div>\n\n\n\n
<\/p>\n\n\n\n1 x 10 is 10\n2 x 10 is 20\n3 x 10 is 30\n4 x 10 is 40\n5 x 10 is 50\n6 x 10 is 60\n7 x 10 is 70\n8 x 10 is 80\n9 x 10 is 90\n10 x 10 is 100<\/pre><\/div>\n\n\n\n
<\/p>\n\n\n\nfor<\/code> loop that executes the code within the loop 10 times over. Here are the three components of our for<\/code> loop:
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int i = 1<\/code> tells our code to start counting from the value 1.<\/li>\n\n\n\ni <= 10<\/code> tells our code to execute the for<\/code> loop only if the value in i<\/code> is less than or equal to 10.<\/li>\n\n\n\n++i<\/code> adds 1 to the i<\/code> variable after the for<\/code> loop has executed. This is called an increment counter.<\/li>\n<\/ul>\n\n\n\n[i counter number] x 10 is<\/code>, followed by the answer to the problem.
<\/p>\n\n\n\nFor Each Loop Java<\/h2>\n\n\n\n
for<\/code> loop you can use to iterate through the contents of the array or collection with which you are working. This is called a for-each<\/code> loop, or an enhanced for loop.
<\/p>\n\n\n\nfor-each<\/code> loop is as follows:
<\/p>\n\n\n\nfor (dataType item : collection) {\n\t\/\/ Execute code\n}<\/pre><\/div>\n\n\n\nfor-each<\/code> loop:
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for<\/code> loop will iterate.<\/li>\n<\/ul>\n\n\n\nfor-each<\/code> loop iterates through each item in the collection, stores each item in the item<\/code> variable, then executes the code stored within the loop body. Let\u2019s walk through an example to discuss how this works.
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<\/p>\n\n\n\npublic class ReducePrices {\n\tpublic static void main(String[] args) {\n\t\tdouble[] prices = {2.50, 2.75, 3.00, 2.75, 2.75, 2.30, 3.00, 2.60};\n\t\tfor (double i : prices) {\n\t\t\tdouble new_price = i - 0.25;\n\t\t\tSystem.out.println(\"The new price is \" + new_price);\n\t\t}\n\t}\n}<\/pre><\/div>\n\n\n\n
<\/p>\n\n\n\nThe new price is 2.25\nThe new price is 2.5\nThe new price is 2.75\nThe new price is 2.5\nThe new price is 2.5\nThe new price is 2.05\nThe new price is 2.75\nThe new price is 2.35<\/pre><\/div>\n\n\n\n
<\/p>\n\n\n\nprices<\/code> which stores the prices for our coffees. This array is declared as an array of doubles, or decimal-based numbers.
<\/p>\n\n\n\nforeach<\/code> loop that runs through each item in the prices<\/code> array. For each item in the array, our program reduces the price of the coffee by 50 cents and assigns the reduced price to the variable new_price<\/code>. Then, our program prints out \u201cThe new price is \u201c, followed by the new price of the coffee.<\/p>\n\n\n\n