46 lines
1.4 KiB
Markdown
46 lines
1.4 KiB
Markdown
---
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title: For Loop
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---
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# For Loop
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The `for` loop executes a block of code until a specified condition is false. Use `while` loops when the number of iterations are variable, otherwise use `for` loops. A common use of `for` loops are array iterations.
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It is also known as an 'entry-controlled loop' since the condition is checked before the next iteration. Another example of an 'entry-controlled loop' is a while loop.
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## Syntax of For Loop
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```c
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for ( init; condition; increment ) {
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statement(s);
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}
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```
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The `for` loop consists of 3 sections, the initialization section, a specific condition and the incremental or decremental operation section. These 3 sections control the `for` loop.
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The initialization statement is executed only once. Then, the test expression is evaluated. If the test expression is false (0), for loop is terminated. But if the test expression is true (nonzero), codes inside the body of for loop is executed and the update expression is updated. This process repeats until the test expression is false.
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The for loop is commonly used when the number of iterations is known.
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## Example
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```c
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#include <stdio.h>
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int main () {
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int array[] = {1, 2, 3, 4, 5};
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for (int i = 0; i < 5; i++) {
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printf("Item on index %d is %d\n", i, array[i]);
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}
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}
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```
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## Output:
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```shell
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> Item on index 0 is 1
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> Item on index 1 is 2
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> Item on index 2 is 3
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> Item on index 3 is 4
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```
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