sizeof () and strlen (1)

sizeof function:

The number of bytes, such as the int type is 4 bytes under the 32 platform, Char is 1 bytes, and any type of pointer is 4 bytes.

Stelen function:

The length of the string, not including '/'.

The following is an example of distinguishing two functions from one-dimensional and two-dimensional arrays:

(1) One-dimensional arrays

int a[] = {1, 2, 3, 4}; printf ("%d\n", sizeof (a)); printf ("%d\n", sizeof (A + 0));p rintf ("%d\n", sizeof (*a));p rintf ("%d\n", sizeof (A + 1));p rintf ("%d\n", sizeof (a[1])); printf ("%d\n", sizeof (&a)); printf ("%d\n", sizeof (&a + 1));p rintf ("%d\n", sizeof (&a[0]));p rintf ("%d\n", sizeof (&a[0] + 1));

Output Result:

16

4

4

4

4

4

4

4

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Analytical:

(2) Two-dimensional arrays

int a[3][4] = {0};p rintf ("%d\n", sizeof (a));p rintf ("%d\n", sizeof (A[0][0]));p rintf ("%d\n", sizeof (A[0]));p rintf ("%d\ n ", sizeof (A[0] + 1));p rintf ("%d\n ", sizeof (A + 1));p rintf ("%d\n ", sizeof (&a[0] + 1));p rintf ("%d\n ", sizeof (*a)); printf ("%d\n", sizeof (a[3]));

Output Result:

48

4

16

4

4

4

16

16

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Analysis of the next article sizeof () and strlen (2)

sizeof () and strlen (1)